light science and magic, fourth edition: an introduction to photographic lighting
TRANSCRIPT
LightScience&MagicFourthEdition
AnIntroductiontoPhotographicLightingA {
FilHunterStevenBiverPaulFuqua
Light—Science&MagicFourthEditionLight—Science&MagicAnIntroductiontoPhotographicLightingFourthEditionFilHunterStevenBiverPaulFuquaAmsterdam•Boston•Heidelberg•LondonNewYork•Oxford•Paris•SanDiegoSanFrancisco•Singapore•Sydney•Tokyo
©
FocalPress
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©2012FilHunter,StevenBiver,andPaulFuqua.PublishedbyElsevier,Inc.Allrightsreserved.
Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans,electronicormechanical,includingphotocopying,recording,orany
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ThisbookandtheindividualcontributionscontainedinitareprotectedundercopyrightbythePublisher(otherthanasmaybenotedherein).
NoticesKnowledgeandbestpracticeinthisfieldareconstantlychanging.Asnewresearchandexperiencebroadenourunderstanding,changesinresearch
methods,professionalpractices,ormedicaltreatmentmaybecomenecessary.
Practitionersandresearchersmustalwaysrelyontheirownexperienceandknowledgeinevaluatingandusinganyinformation,methods,compounds,or
experimentsdescribedherein.Inusingsuchinformationormethodstheyshouldbemindfuloftheirownsafetyandthesafetyofothers,includingpartiesforwhom
theyhaveaprofessionalresponsibility.
Tothefullestextentofthelaw,neitherthePublishernortheauthors,contributors,oreditors,assumeanyliabilityforanyinjuryand/ordamagetopersonsor
propertyasamatterofproductsliability,negligenceorotherwise,orfromanyuseoroperationofanymethods,products,instructions,orideascontainedinthe
materialherein.
LibraryofCongressCataloging-in-PublicationDataHunter,Fil.
Light—science&magic/FilHunter,StevenBiver,andPaulFuqua.—4thed.p.cm.
ISBN978-0-240-81225-0
1.Photography—Lighting.I.Fuqua,Paul.II.Biver,Steven.III.Title.
TR590.H842011778.7'2—dc23
2011018511
BritishLibraryCataloguing-in-PublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
ForinformationonallFocalPresspublicationsvisitourwebsiteatwww.elsevierdirect.com
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ELSEVIERSabreFoundationIntroductionItgivesus,yourauthors,greatpleasuretowelcomeyoutothisnewedition.WewouldalsoliketothankyouforallthesupportyouhaveshownforLight—Science&Magicoverthe
pastnearquarterofacentury.Wesincerelyappreciateit.
Sinceourpreviousedition,thephotographer'sworld—andeverybodyelse's—haschangedradically.Longestablished
markets,relationships,andbusinessmodelshaveshrunk,ifnotcompletelycollapsed.Oncevaluedskillsetshavebeen
rendereduseless,andthefeesclientsarewillingtopayhavebeenreducedineverymarketsector.Allinall,it’sfairtosay
thatnotallthingsarerosyintoday'sstressed-outimage-makingworld.
Thereis,however,alsoagood—averygood—sidetothings.Whileitistruethatontheonehandwephotographersmay
bechallengedasperhapsneverbefore,itisalsotruethatoverthepastseveralyearsmanufacturershaveswampeduswith
aseeminglyendlessfloodoftrulyamazinggear.Newgenerationsofcameras,lightinggear,high-resolutionprinters,and
sophisticatedsoftwarehaverevolutionizedhowweworkandhowwethink.
Today,itiscommonplaceforustodothatofwhichwecouldnotevendreamthosefewyearsagowhentheprevious
editionofthisbookrolledoffthepresses.Andsoitgoes.Insomewaysweareworseoffthanweoncewere.Inothers,we
arebetteroff.
Andthenthereislight—thecollectiveresultofallthosebusylittlephotonsthatbuzzaroundtheuniverseastheyhave
sinceitscreation.Lightiseverythingforus.Lightis,alwayshasbeen,andalwayswillbetheveryfoundationofthat
amazingamalgamationofartandsciencewecallphotography.Andnow,thankstoyourcontinuedsupport,thereisthis,
thenewesteditionofLight—Science&Magic.Ourgreatesthopeforitisthatitwill,likeearliereditions,helpstudentsto
understandhowlightbehaves,andalwayswill.Armedwiththesetimelessprinciples,oneisreadytodobattle—and
thoroughlyenjoyit—inthisnewandcrazyworldofpicturemaking.
123
TryaLensPolarizingFilter56
Dark-FieldLighting8
PortableFlashwithMotion910
1
HowtoLearnLighting
Light—Science&Magicisadiscussion,notalecture.Youbringtothisdiscussionyourownopinionsaboutart,beauty,
andaesthetics.Wedonotintendtochangethoseopinionsandmaynoteveninfluencethemverymuch.Wewillbemore
boredthanflatteredifreadingthisbookcausesyoutomakepicturesthatlooklikeours.Forbetterorworse,youhaveto
buildyourownpicturesonyourownvision.
Whatwedohavetoofferyouisasetoftools.Thisbookisabouttechnology.Science.Brasstacks.Itisinformationfor
youtousewhenyouplease,ifyouplease,andhowyouplease.Thisdoesnot,however,meanthatthisbookisnotabout
ideas,becauseitis.Thebasictoolsoflightingareprinciples,nothardware.Shakespeare'stoolwastheElizabethanEnglish
language,notaquillpen.AphotographerwithoutmasteryoflightingislikeaShakespearewhocouldspeakonlythe
languageofthepeopleintheGlobeTheatrepit.BeingShakespeare,hestillmighthavecomeupwithadecentplay,butit
certainlywouldhavetakenalotmoreworkand,verylikely,moreblindluckthanmostpeopleareentitledtoexpect.
Lightingisthelanguageofphotography.Patternsoflightconveyinformationjustassurelyasspokenwords.The
informationthatlightconveysisclearandspecific.Itincludesdefinitestatements,suchas“Thebarkofthistreeisrough”
or“Thisutensilismadeofstainlesssteel,butthatoneissterling.”
Lighting,likeanyotherlanguage,hasagrammarandavocabulary.Goodphotographersneedtolearnthatgrammarand
vocabulary.Fortunately,photographiclightingisaloteasiertomasterthanaforeignlanguage.Thisisbecausephysics,
notsocialwhim,makestherules.
Thetoolswehaveincludedinthisbookarethegrammarandvocabularyoflight.Whateverwesayaboutspecific
techniqueisimportantonlytotheextentthatitprovestheprinciples.Please,donotmemorizethelightingdiagramsinthis
book.Itisentirelypossibletoputalightinexactlythesamespotshowninthediagramandstillmakeabadpicture—
especiallyifthesubjectisnotidenticaltotheoneinthediagram.Butifyoulearntheprinciple,youmayseeseveralother
goodwaystolightthesamesubjectthatwenevermentionandmaybeneverthoughtof.
WHATARE“THEPRINCIPLES”?
Tophotographers,theimportantprinciplesoflightarethosethatpredicthowitwillbehave.Someoftheseprinciplesare
especiallypowerful.Youwillprobablybesurprisedtofindhowfewtheyare,howsimpletheyaretolearn,andhowmuch
theyexplain.
WediscussthesekeyprinciplesindetailinChapters2and3.Theyarethetoolsweuseforeverythingelse.Inlater
chaptersweputthemtoworktolightawiderangeofsubjects.Atthispointwewillsimplylistthem:
1.Theeffectivesizeofthelightsourceisthesinglemostimportantdecisioninlightingaphotograph.Itdetermineswhat
typesofshadowsareproducedandmayaffectthetypeofreflection.
2.Threetypesofreflectionsarepossiblefromanysurface.Theydeterminewhyanysurfacelooksthewayitdoes.
3.Someofthesereflectionsoccuronlyiflightstrikesthesurfacefromwithinalimitedfamilyofangles.Afterwedecide
whattypeofreflectionisimportant,thefamilyofanglesdetermineswherethelightshouldorshouldnotbe.
Justthinkaboutthatforaminute.Ifyouthinklightingisanart,you'reexactlyright—butit'salsoatechnologythatevena
badartistcanlearntodowell.Thesearethemostimportantconceptsinthisbook.Ifyoupaycloseattentiontothem
whenevertheycomeup,youwillfindtheywillusuallyaccountforanyotherdetailsyoumayoverlookorweforgetto
mention.
WHYARETHEPRINCIPLESIMPORTANT?
Thethreeprincipleswehavejustgivenarestatementsofphysicallawsthathavenotchangedsincethebeginningofthe
universe.Theyhavenothingtodowithstyle,taste,orfad.Thetimelessnessoftheseprinciplesisexactlywhatmakesthem
souseful.Consider,forexample,howtheyapplytoportraitstyle.Arepresentative1952portraitdoesnotlooklikemost
portraitsmadein1852or2012.However,andthisistheimportantpoint,aphotographerwhounderstandslightcould
executeanyofthem.
Chapter8showssomeusefulapproachestolightingaportrait.Butsomephotographerswillnotwanttodoitthatway,and
evenfewerwilldosoin20years.Wedonotcarewhetherornotyouusethemethodofportraitlightingwechoseto
demonstrate.Wedo,however,careverymuchthatyouunderstandexactlyhowandwhywedidwhatwedid.Itisthe
answerstothosevery“hows”and“whys”thatwillallowyoutoproduceyourownpicturesyourownway.Goodtoolsdo
notlimitcreativefreedom.Theymakeitpossible.
Goodphotographstakeplanning,andlightingisanessentialpartofthatplanning.Forthisreason,themostimportantpart
ofgoodlightinghappensbeforeweturnonthefirstlights.Thisplanningcantakemanydaysoritcanhappenafractionof
asecondbeforepressingtheshutterrelease.Itdoesnotmatterwhenyouplanorhowlongittakes,aslongasyougetthe
planningdone.Themoreyouaccomplishwithyourhead,thelessworkyouhavetodowithyourhands—youcanthink
fasterthanyoucanmove.
Understandingtheprincipleswepresentedearlierenablesustodecidewhatlightsneedtobewherebeforewebeginto
placethem.Thisistheimportantpart.Therestisjustfine-tuning.
HOWDIDWECHOOSETHEEXAMPLESFORTHISBOOK?
Theportraitisbutoneofthesevenbasicphotographicsubjectswediscuss.Wechoseeachsubjecttoprovesomething
aboutthebasicprinciples.Wealsolitthesubjecttoshowtheprinciple,regardlessofwhethertheremightbeothergood
waystolightthesamething.Ifyouknowtheprinciples,youwilldiscovertheotherwayswithoutanyhelpfromus.
Thismeansthatyoushouldgiveatleastsomeattentiontoeveryrepresentativesubject.Evenifyouhavenointerestina
particularsubject,itprobablyrelatestosomethingyoudowanttophotograph.
Wealsochosesomeofthesubjectsbecausetheyarerumoredtobedifficult.Suchrumorsarespreadusuallybypeople
wholackthetoolstodealwithsuchsubjects.Thisbookdispelstherumorsbygivingyouthosetools.
Inaddition,wetriedtousestudioexampleswheneverpossible.ThisdoesnotmeanLight—Science&Magicisonlyabout
studiolighting.Farfromit!Lightbehavesthesamewayeverywhere,whetheritis
controlledbythephotographer,bythebuildingdesigner,orbyGod.Butyoucansetupindoorexperimentslikeoursat
anyhourofanydayregardlessoftheweather.Later,whenyouusethesamelightinginalandscape,onapublicbuilding,
oratapressconference,youwillrecognizeitbecauseyouwillhaveseenitbefore.
Finally,wechoseeachexampletobeassimpleaspossible.Ifyouarelearningphotography,youwillnothavetoleavethe
setupinyourlivingroomorinyouremployer'sstudiofordaysatatimetomasterit.Ifyouteachphotography,youwill
findthatyoucandoanyofthesedemonstrationsinasingleclasssession.
HowWeCreatedtheCover
BeforethepublishingofthisfourtheditionofLight—Science&Magic,severalofthosewhosawitscoveraskedhowourco-author,StevenBiver,
madeit(Figure1.1).Withthatinmind,weofferthefollowingexplanation:
Thebasicsetup.ThefirstthingthatStevendidwastoplaceasheetofglossyblackPlexiglasonhisstudiotable(Figure1.2).Next,hesuspended
frosteddiffusionmaterialaboveitasshowninthediagram.(Thiscouldhavebeendoneinanynumberofways.Stevenchoseto
1.1Thisisthecoverimagewithoutthetype.
1.2LightingDiagramForCoverImage
clampittothebackofthetableandattachittoabarsuspendedbetweentwostandsatthefront.)
Thelights.Oncehehadthetableanddiffuserarranged,Stevensetupthetwolightsheplannedonusing.Thefirst,hismainlight,wasaflashhead
fittedwithasmallreflectortowhichheattachedanambergel.Hethensecuredthislighttoaboomandsuspendeditoverthecenterofthediffusion
material,andabout1.5feetaboveit.Next,Stevenfittedasmallreflectorwithatightgridtowhichheattachedapurplegel.Hethenputthisheadon
asmallstandandplaceditclosetoandcameraleftofhiscamera.
The“pose."Thearrangementoftheclearacrylicballsontheblackwasverymuchaworkinprogress.Becausetheballstendedtorolloffthetable
atinappropriatemoments,Stevenresortedtoholdingeachinplacewithatinybitofwax.Later,duringpostproduction,hedigitally“airbrushed”
awayanyofthesethatshowed.
Theresults.WhenStevenmadehisexposures,theamber-coloredmainlightproducedasoft,circularglowinthemiddleofhiscomposition.The
gridspotatthefrontofhissetupproducedthesmallpurplehighlightsonalltheacrylicballs.Inaddition,becauseofrefraction,bothlights
producedevensmallersecondaryhighlightsonalltheballs.
Andfinally.Thiswasaninterestingshottomake.Weencourageanyofyouwhomightbeinterestedtotrymakingasimilarimage.Aquickcheck
onlinewillprovideplentyofsourcesforthekindsofPlexiglassheeting,diffusionmaterial,andacrylicballsStevenused.
Wewouldlovetoseetheresultsofyourefforts.Sowouldplentyofotherphotographers.Andthat’swhattheLight—Science&MagicsiteonFlickris
allabout.Sogoaheadandpostyourwork.Becomeamemberofthe“family.”
TODO,ORNOTTODO?
Ifyouarelearningphotographywithoutanyformalinstruction,wesuggestyoutryallofthebasicexamplesinthisbook.
Donotsimplyreadaboutthem.Whathappensinyourheadisthemostimportantpartoflighting,buttheeyeandthehand
arestillessential.Guidedexperiencecoordinatesthethree.
Whenwetalkaboutsoftshadowsorpolarizeddirectreflections,forexample,youalreadyknowhowtheylook.They
happenintheworld,andyouseethemeveryday.Butyouwillknowthemandseethemstillbetteronceyouhavemade
themhappen.
Ifyouareastudent,yourclassassignmentswillkeepyoubusyenoughwithoutanyfurtherdemandsfromus.Yourteacher
mayusetheexerciseshereorinventnewones.Eitherway,youwilllearntheprinciplesinthebookbecausetheyarebasic.
Theyhappeninalllightingsituations.
Ifyouareaprofessionalphotographertryingtoexpandyourareasofexpertise,yourjudgmentaboutwhatexercisesyou
needisbetterthanours.Generally,thesewillbethosethatareleastlikethethingsyouarealreadyphotographing.You
mayfindourbasicexamplestobetoosimpletobeanentertainingchallenge.Trycomplicatingthingsabit.Addan
unexpectedprop,anunusualviewpoint,oraspecialeffecttoourbasicexample.Youmightaswellgetastrikingportfolio
pieceoutoftheeffortwhileyouareatit.
Ifyouareateacher,youcanlookatthisbookandseethatmostoftheexercisesshowatleastonegood,simple,easy-to-
masterwaytolighteventhosesubjectswithreputationsformaximumdifficulty:metal,glass,whiteonwhite,andblack
onblack.
Notice,however,thatalthoughwe'vedonethisinalmosteverycase,weweren'tabletodoitinabsolutelyeveryoneof
them.The“invisiblelight”exerciseinChapter6,forexample,isprettydifficultformostbeginners.Somestudentsmay
alsofindthesecondarybackgroundbehindtheglassofliquidinChapter7tobebeyondthelimitoftheirpatience.Forthis
reason,ifyoufindanythinginthisbookthatyouhaven'talreadydonewithyourownhandsandeyes,westrongly
encourageyoutobesuretotryityourselfbeforedecidingwhetheritisappropriatetotheskillsofyourstudents.
WHATKINDOFCAMERADOINEED?
Asking“WhatkindofcameradoIneed?”mayseemsillytoexperiencedphotographers.Butwehavetaughtthismaterial.
Weknowhowmanystudentsaskit,andwehavetoanswerit.Therearetwogoodanswers,andtheycontradicteachother
slightly.Theweightweplaceoneachanswermattersmorethantheanswersthemselves.
Successfulphotographsdependonthephotographermorethantheequipment.Inexperiencedphotographersworkbest
withthecamerawithwhichtheyarefamiliar.Experiencedphotographersworkbestwiththecameratheylike.These
humanfactorssometimeshavemoretodowiththesuccessofaphotographthanthepurelytechnicalprinciples.
Ideally,peoplelearningphotographyshouldshootdigitallyfortheinstantfeedbackthisapproachprovides.Shooting
digitallyisfarlessexpensive,andthequalitythatmanyoftoday'sdigitalcamerasprovidebordersonamazing.Ofthe
manyphotographsinthisbook,wemadeallbutahandfuldigitally.
Justwhichdigitalcamerayoushouldgetisuptoyou.Fortunately,mostmanufacturersofferanumberofreasonably
pricedcameras.Checkoutthemanyreviewsthatyouwillfindinphotographymagazinesandontheweb.Talktoother
photographersand,ifpossible,dealwithacamerastorewhosesalesstaffknowswhattheyaretalkingabout.Cameraclubs
arealsoanothergoodsourceofinformation,andifyouareinschool,yourinstructorwillalsobeabletohelpyouselect
thecamerathatbestfitsyourneedsandbudget.
AWORDOFCAUTION
Anywayyoulookatit,theadventofthedigitalworldhasbeenawonderfulthingforstudents.Itisnot,however,atotally
win-winsituation.Anydigitalcamerais,atitsheart,acomputer.Becauseofthis,thecameramakercanprogramthe
cameratoaltertheimagewithouttheforeknowledgeorconsentofthephotographer!Thisisoftenagoodthing.The
camera'sdecisionsare,inourexperience,moreoftenthannotcorrect.Sometimes,however,theyarenot.
Astillbiggerproblemisthatitisharderforthestudenttoknowwhetherwhat'shappened,forbetterandforworse,is
becauseofthecamera'sdecisionorbecauseofthephotographer'sdecision.Youmaymakemistakesthatthecamerafixes,
costingyoualearningexperience,orthecameracanmakeamistakeandyouinnocentlyblameyourselfforit.
Inlightoftheprecedingparagraphs,weoffertwosuggestions:
1.Developatleastaminimalcompetenceinpostproductionskills.Youdonothavetobeawhiz-bangPhotoshopgeniusto
beaneffectivedigitalshooter.Youdo,however,needtolearnatleastthebasicsofoneofthenumerous(andnowoften
amazinglyinexpensive)digitaleditingprogramsthatarenowavailable.
2.ShootintheRawformat.Becauseofitsminimalin-cameracompression,itstoresfarmoreofthevisualinformation
thatreachesyourcamera'ssensorthandoesthealternateJPEGformat.Thus,duringpostproductionwhenyouarefine-
tuningyourimages,yoursoftwarehasfarmoredigitalinformationwithwhichtowork.Andthiscanmakeabig
difference—averybigdifference.
Unfortunately,thisbookdoesnothavethespaceneededtodealwiththeabovetwoissuesindetail.Digitalcamerasand
postproductionsoftwaredifferfromeachotherbecauseofthemanydecisionstheirdesigners,programmers,and
manufacturershavemade.Ifyouareastudent,theremedyforthisisaclose,ongoingtalkwithyourinstructorabout
what'shappeninginyourpictures.Ifyouareanexperiencedphotographer,youcanalreadytellwhenthecameraishelping
youandwhenitishurtingyou.
Thehardestpathisthatofanovicephotographerattemptingtolearnthematerialinthisbookwithoutthebenefitofformal
instruction.Whatwecanofferthosephotographersistheassurancethatthematerialcan,indeed,belearnedexactlythat
way.Allthreeoftheauthorsofthisbookdidso.Talkwithotherphotographersasmuchaspossible.Askquestions,and
alwayssharewithotherswhateveryouhavelearned.
WHATLIGHTINGEQUIPMENTDOINEED?
Weexpectyoutoaskthisquestion,andweofferthistwo-partanswer:
1.Nophotographerhasenoughlightingequipmenttodoeveryassignmentaswellaspossible.Nomatterhowmuch
lightingequipmentyouhave,therewillbetimeswhenyouwantmore.Suppose,forexample,youcanilluminatealarge
settoshootatf/96at1/5000asecond.(Pleasecallthefiredepartmentbeforeturningonthisapparatus.)Youwillprobably
thenfindthatyouwantstillmorelightinaparticularshadow,oryoumayfindthatyouneedtolightastilllargerareatofit
therequiredcomposition.
2.Mostphotographershaveenoughequipmenttodoalmosteveryassignmentwell.Evenifyouhavenolighting
equipmentatall,youmaybeabletogetthejobdone.Canthesubjectbephotographedoutdoors?Ifnot,sunlightthrougha
windowmaybeagoodlightsource.Inexpensivetools,suchaswhitecloth,blackpaper,andaluminumfoil,canallowyou
tocontrolsunlightaseffectivelyasthebestmanufacturedequipment.
Goodlightingequipmentisagreatconvenience.Ifthesunmovestoofaracrosstheskybeforeyouarereadytoexpose,
youmayhavetowaituntilitreturnsthenextdayandhopethereisnomoreandnolesscloudcoverthesecondtime
around.Professionalphotographersknowthatconveniencebecomesnecessitywhentheyhavetophotographwhatthe
clientwantswhentheclientwants.
Thismessageisnotaimedatprofessionals,however.Theyalreadyknowhowtodowhateverisneededwithwhateveris
available.Wearemoreinterestedinencouragingstudentsnow.Youhaveadvantagesthatprofessionalsdonot.Within
broadlimits,youcanselectthesizeofyoursubject.
Smallscenesrequirelesslight.Youmaynothavea3-by-4-footsoftbox,butadesklampwitha60-wattbulbwitha
tracingpaperdiffusercanlightasmallsubjectnearlyaswell.
Lackofequipmentis,nodoubt,ahandicap.Youknowitandweknowit.Butitisnotnecessarilyaninsurmountable
obstacle.Agooddoseofcreativitymaywellovercomeit.Justrememberthatcreativelightingistheresultofplanningthe
lighting.Partofthatcreativitymeansanticipatingthelimitationsanddecidinghowtobestworkaroundthem.
WHATELSEDOINEEDTOKNOWTOUSETHISBOOK?
Weassumeyouknowbasicphotography.Youknowhowtodetermineareasonableexposure,atleastcloseenoughthat
bracketingcancovererrors.Youunderstanddepthoffield.Youhavemasteredthebasicoperationofyourcamera.
Thatisall.Wehavenointentionofbeingruthlessinourexaminationofyourbackgroundcredentials.Justtobesafe,
however,wesuggestyoukeepagoodbasicphotographybookonhandwhenyoureadthisone.(Wedidwhenwewrote
it.)Wedonotwantyoutofindeasymaterialdifficultjustbecauseweunknowinglyuseatechnicaltermyouhavenotseen
before.
Finally,donotoverlooktheInternet.Thereisawealthofinformationonitaboutlightingandphotography.Asearchhere
andasearchtherearemomentswellspentbyanyphotographer,advancedorbeginner.
WHATISTHE“MAGIC”PARTOFTHISBOOK?
Learnaboutthelightandthescience.Themagicwillhappen.
2
Light:TheRawMaterialofPhotography
Insomeways,photographersresemblemusiciansmorethanpainters,sculptors,andothervisualartists.Thisisbecause
photographers,likemusicians,aremoreinterestedinthemanipulationofenergythanthatofmatter.
Photographybeginsthemomentlightisemittedfromasource.Itclimaxeswithstillmorelightreflectedfromaprinted
pageorbeamingfromamonitorandstrikingahumaneye.Allstepsbetweenmanipulatelight,whethertocontrolit,to
recordit,or,ultimately,topresentittoaviewer.
Photographyisthemanipulationoflight.Whetherthosemanipulationsserveartisticortechnicalpurposeshardlymatters;
thetwoareoftensynonymous.Whetherthemanipulationsarephysical,chemical,electrical,orelectronic,theyareall
motivatedbythesamemissionandguidedbythesameunderstandingofhowlightbehaves.
Inthischapterwearegoingtotalkaboutlight,therawmaterialfromwhichwemakepictures.You,reader,arealready
familiarwithmostoftheideaswewilldiscuss.Thisisbecauseyouhavebeenlearningtoseesincethedayyouwereborn.
Evenifyouhappentobeanovicephotographer,theoccipitallobeofyourbrainhasenoughinformationaboutthe
behavioroflightforyoutobeamaster.
Wewanttoattachwordsandlabelstosomeofthisunconsciousandsemiconsciousinformation.Thiswillmakeiteasier
forustotalkaboutlightwithotherphotographers,justasmusiciansfinditeasiertosay“bflat”or“4/4time”insteadof
hummingascaleortappingarhythm.
Thisisthemosttheoreticalchapterinthisbook.Itisalsothemostimportantbecauseitisthefoundationforallthat
follows.
WHATISLIGHT?
Acompletedefinitionofthenatureoflightiscomplex.Infact,severalNobelPrizeshavebeenawardedforvarious
contributionstotheworkingdefinitionweusetoday.Wewillsimplifyourdiscussionbyusingadefinitionadequatefor
appliedphotography.Ifyouarestillcuriousafterreadingthis,seeanybasicphysicstext.
Lightisatypeofenergycalledelectromagneticradiation.Electromagneticradiationtravelsthroughspaceintiny
“bundles”calledphotons.Aphotonispureenergyandhasnomass.Aboxofphotonsthesizeofanelephantweighs
nothing.
Theenergyofthephotonproducesanelectromagneticfieldaroundthephoton.Afieldisinvisibleandcannotbedetected
unlessthereisamaterialobjectinthefieldonwhichitcanexertaforce.Thissoundsprettymysteriousuntilwerealize
thatonecommonexampleofafieldisthemagneticfieldsurroundinganordinarymagnet.Wecannottellthefieldexists
unlesswemoveanailcloseenoughforthemagnettoattractit.Thentheeffectofthefieldisapparent:thenailjumpsto
themagnet.
Unlikethefieldaroundthemagnet,however,theelectromagneticfieldaroundthephotonisnotconstantinstrength.
Instead,itfluctuatesasthephotontravels.Ifwecouldseethischangeinthestrengthofthefielditwouldlooksomething
likeFigure2.1.
Noticethatthestrengthofthefieldmovesfromzerotoitsmaximum-positivestrengthsandthenbacktozero;itthen
repeatsthepatterninthenegativedirection.Thisiswhythefieldaroundabeamoflightdoesnotattractmetallikeaniron
magnetdoes.Thefieldaroundaphotonoflightispositivehalfofthetimeandnegativetherestofthetime.Theaverage
chargeofthetwostatesiszero.
Asthetermimplies,anelectromagneticfieldhasbothanelectricalcomponentandamagneticone.Eachcomponenthas
thesamepatternoffluctuation:zerotopositive,tozero,tonegative,andbacktozeroagain.Theelectricalcomponentis
perpendiculartothemagneticone.
TherelationshipbetweenthesetwocomponentsiseasiertoseeifweassumethatFigure2.1representsjustthemagnetic
component.Then,ifyouturnthisbooksothattheedgeofthepageistowardyou,thesamediagramwillrepresentthe
electricalfield.Wheneverthestrengthofeitherthemagneticortheelectricalcomponentisatitsmaximum,theotherisat
itsminimum,sothetotalfieldstrengthremainsconstant.
Allphotonstravelthroughspaceatthesamespeed,buttheelectromagneticfieldofsomephotonsfluctuatesfasterthan
thatofothers.Themoreenergyaphotonhas,thefasterthefluctuation.Humaneyescanseetheeffectofthisdifferencein
photonenergylevelsandinthe2.1Themagneticfieldaroundaphotonfluctuatesfromitsmaximum-positivetoitsmaximum-negativestrengthasthephotontravels.Theelectricalfieldbehavesexactlythesamebutoutofphasewiththemagneticfield;wheneveronefieldisatits
maximum,theotherisatitsminimumstrength.
rateoffieldfluctuation.Wecalltheeffectcolor(Figure2.2).Redlight,forexample,haslessenergythanbluelight,sothe
rateofitselectromagneticfieldfluctuationisonlyabouttwothirdsasfast.
Wecalltherateoffluctuationoftheelectromagneticfielditsfrequency,andwemeasureitwiththeunitcalledHertz,or,
forconvenience,megahertz(1megahertz=1,000,000Hertz).Hertzisthenumberofcompletewavelengthsthatpassa
pointinspaceeachsecond.Visiblelightisonlyonenarrowrangeoutofallthemanypossibleelectromagnetic
frequencies.
Electromagneticradiationcantravelthroughavacuumandthroughsomeformsofmatter.Weknowthatlight,for
example,canpassthroughtransparentglass.Electromagneticradiationisnotcloselyrelatedtomechanicallytransmitted
energy,suchassoundorheat,MagneticORElectricalFieldStrength
2.2Therateatwhichtheelectromagneticfieldfluctuatesvaries.Weperceivethisvariationasdifferentcolorswhichcantravelonlythroughmatter.(Infraredradiationandheatareoftenconfusedbecausetheytendtoaccompanyoneanother.)Sunlightreaches
Earth,andverymuchbeyond,withoutanyfiber-opticlinestogetithere.
Moderncamerasaresensitivetoawiderrangeofelectromagneticfrequenciesthanthehumaneyecanperceive(Figure
2.3).Thisiswhyapicturecanbedegradedbyultravioletlight,whichwecannotseeinalandscape,and,evenworse,film
canbedegradedbyx-rays,whichwecannotseeemittedbyamachineatanairport.
HOWPHOTOGRAPHERSDESCRIBELIGHT
Evenifweconfineourattentiontothevisibleportionoftheelectromagneticspectrum,everyoneknowsthattheeffectof
onegroupofphotonsmayberadicallydifferentfromthatofanother.Examiningouralbumofmentalimages,weallsee
thedifferencebetweenanautumnsunset,awelder'sarc,andanearlymorningfog.Eveninastandard
2.3Thisdiagramshowstheelectromagneticspectrum.Noticethatvisiblelightisonlyonesmallpartofit.
officelocation,thedecisiontoinstallfluorescenttubes,tungstenspots,orlargeskylightscanhaveamajoreffectonthe
decor(aswellasonthemoodandtheproductivityoftheoccupants).
Photographers,however,areinterestedinmorethanjustthementalimagesofagivenlightingeffect.Theyneedtechnical
descriptionsoftheeffect.Beingabletodescribethelightisthefirststepinbeingabletocontrolit.Orifthelightisnot
controllable,asitisnotinalandscapeoranarchitecturalpicture,describingthelightimpliesseeingthelightwellenough
toknowwhethertoshootortowaituntilconditionsimprove.
Asphotographers,weareprimarilyconcernedwiththebrightness,color,andcontrastofthelight.Inthefollowingpages,
wewilltakeabrieflookateach.
Brightness
Toaphotographer,thesinglemostimportantqualityofalightsourceisitsbrightness.Abrighterlightisalmostalwaysa
betterlight.
Atthemostbasiclevel,ifthelightisnotbrightenough,wecannotgetapicture.Ifthelightisbrighterthantheminimum
wemusthave,thenwecanprobablygetabetterpicture.
Photographerswhousefilmcanuseasmallerapertureorafastershutterspeediftheyhavemorelight.Iftheydonot
need,orwant,asmallerlensopeningorashorterexposuretime,thenmorelightallowsusingaslower,finergrainedfilm.
Eitherway,theimagequalityimproves.
Eveniffilmisirrelevant,thebrightnessofthelightsourcestillisimportant.Videographerspreferasmalleraperturefor
mostshots,asdostillandmotionpicturephotographers.Furthermore,adequateilluminationallowsavideographerto
foregoboostingthegainonthecamera.Thisproducessharperpicturesonthescreenwithbettercolorsaturationandless
videonoise.
Usuallyphotographerspreferadimmerlightsourceonlywhenthereisanaestheticimprovementinoneoftheother
qualitiesoflight:thecolororthecontrast.
Color
Wecanuselightofanycolorweplease,andverystronglycoloredlightsfrequentlymakeanartisticcontributiontothe
photograph.Nevertheless,mostpicturesaremadewithwhitelight.However,even“white”lightcomesinarangeof
colors.Photographersconsiderlighttobe“white”whenitisaroughlyevenmixofthethreeprimarycolors:red,blue,and
green.Humanbeingsperceivethiscombinationoflightcolorstobecolorless.
Theproportionsofthecolormixturemayvarytoagreatextent,andpeoplestillcannotperceiveanydifference,unless
theyhavethedifferentlightsourcessidebysideforcomparison.Theeyecandetectaveryslightchangeinthecolor
mixture,butthebrainrefusestoadmitthedifference.Aslongasthereisareasonableamountofeachprimarycolor,the
brainsays,“Thislightiswhite.”
Digitalcamerasmakethesameautomaticadjustmenttocolorthatthebraindoes,butnotnearlyasreliably.Photographers
mustthereforepayattentiontothedifferencesbetweenvariouswhitelightsources.Toclassifyvariationsinthecolorof
whitelight,photographersborrowthecolortemperaturescalefromphysicists.Thecolortemperaturescaleisbasedonthe
factthatifweheatamaterialinavacuumhotenough,itwillglow.Thecolorofthisglowdependsonhowmuchweheat
thematerial.WemeasurecolortemperatureindegreesontheKelvintemperaturescale.Themeasurementunit,degrees
Kelvin,issimplyabbreviated“K.”
Itisinterestingthatlightwithahighcolortemperatureiscomposedofadisproportionateamountofthosecolorsartists
callcool.Forexample,10,000°Klighthasagreatdealofblueinit.Similarly,whatphysiciststellusisalowtemperature
sourcehasmuchofthosecolorsartistscallwarm.Thus,a2000°Klighttendstowardtheredtoyellowfamilyofcolors.
(Noneofthisissurprising.Anyweldercantellusthattheblue-whiteweldingarcishotterthanthepieceofred-hotmetal
gettingwelded.)Photographersusethreestandardlightcolortemperatures.Oneoftheseis5500°Kandiscalleddaylight.Therearetwotungstencolortemperaturestandards,3200°Kand3400°K.Thelasttwoarecloseenoughtogetherthat
sometimesthedifferencebetweenthemdoesnotmatter.Thesethreelightstandardsweredevelopedforfilm,andwecan
stillbuyfilmthatiscolorbalancedforanyofthesethreelightcolorstandards.Digitalcameras,however,offermuchmore
flexibilitybyadjustingnumbersinthedataprocessingtoeffectivelyallowshootingproperlycolor-balancedpicturesnot
onlywithlighttemperaturesbetweenanytwoofthethreestandardsbutalsoattemperaturesmuchlowerthan3200°Kand
muchhigherthan5500°K.
Contrast
Thethirdimportantcharacteristicofaphotographiclightisitscontrast.Alightsourcehashighcontrastifitsraysallstrike
thesubjectfromnearlythesameangle.Lightraysfromalow-contrastsourcestrikethesubjectfrommanydifferent
angles.Sunlightonacleardayisacommonexampleofahigh-contrastlightsource.TheraysofsunlightinFigure2.4are
paralleltooneanotherandallstrikethesubjectfromthesameangle(despitetheapparentdifferenceinanglecausedhere
byhavingtodrawthreedimensionsonflatpaper).
Theeasiestwaytorecognizeahigh-contrastlightsourceistheappearanceoftheshadows.Inthediagram,weseethatno
lightenterstheshadowarea.Thiscausestheedgeoftheshadowtobesharpandclearlydefined.WemadeFigure2.5with
suchalightsource.Noticethecrisp,hard-edgedshadowofthepepper.
Ashadowwithsharplydefinededgesiscalledahardshadow.Forthisreason,high-contrastlightsourcesarealsosaidto
behardlights.
Nowletusimaginewhathappenswhencloudcoverobscuresthesun.LookatFigure2.6.Thesunlightscattersasitpasses
throughthecloud.Consequently,thelightthatpassesthroughthecloudsstrikesthesubjectfrommanydifferentangles.
Therefore,onanovercastdaysunlightbecomesalow-contrastlightsource.
2.4Theraysfromasmall,high-contrastlightsourceallstrikeasubjectatapproximatelythesameangle,producingahard-edgedshadow.
2.5Hard-edgedshadowsarecharacteristicallyproducedbysmalllightsources.
2.6Thecloudscattersthesun’slightrays,causingthemtostrikethesubjectfrommanyangles.Thisproducesthesoftshadowcharacteristicoflargelights.
Again,thecontrastofthelightsourceisrevealedbytheappearanceoftheshadow.Someoftheraysoflightpartly
illuminatetheshadow,especiallyatitsedge.ThisdifferenceisapparentinFigure2.7.
Inthephotographusinglow-contrastlight,theshadowofthepepperisnolongerclearlydefined.Itisnolongerhard.The
viewercannotdecideexactlywhatpartofthetabletopisinshadowandwhatisnot.Ashadowsuchasthisone,withno
clearlydefinededge,iscalledasoftshadow,andthelightproducingitiscalledasoftlight.
Noticethatweareusingthewordshardandsoftonlytodescribehowsharplytheedgeofashadowisdefined.Wearenot
usingthesetermstodescribehowlightordarktheshadowis.Noticethatthecenterofeachshadowisaboutthesamegray
ineachpicture.Asoftshadowmaybeeitherlightordark,justasahardshadowmaybeeitherlightordark,dependingon
factorssuchasthesurfaceonwhichitfallsandhowmuchlightgetsreflectedintotheshadowbynearbyobjects.
Forsinglelightsources,thesizeofthatsourceistheprimaryfactorinfluencingitscontrast.Asmalllightsourceisalways
ahardlightsource,andmostlargesourcesaresoftones.WeseethatthesuninFigure2.4occupieslittleareainthe
diagram,soitisasmalllightsource.ThecloudcoversagreaterareainFigure2.6,makingitalargesource.
2.7Ashadowsosoftthatmuchofitisjustbarelyvisibleistheresultofaverylargelightsource.
Noticethatthephysicalsizeofalightdoesnotcompletelydetermineitseffectivesizeasaphotographiclightsource.We
knowthatthesunismorethan1millionkilometersindiameter.However,itisfarenoughawaytoactasasmallsource
foraphotographicsubjectonEarth.
Ifwecouldmovethesuncloseenoughtous,itwouldbecomeanextremelylargelightsource.Wecouldthenmakesoftly
litphotographsinsunlight,evenwithoutanycloudcover,assumingwecouldfindasolutiontotheheatproblem!Another
extremeexamplehasamorepracticaluse:asmalllamponalaboratoryworkbenchcanbeaneffectivelylargesourceif
weputitcloseenoughtoaninsectspecimen.
Beaware,however,thatthecorrelationbetweenthesizeofalightsourceanditscontrastisjustagenerality,notan
absolute.Rememberthatwecanopticallyalteralightwithspecialattachments.Forexample,aspotattachmentcanfocus
thelightraysofastrobehead,Thecontrastofthelightisonlyoneoftheinfluencesonthecontrastofaphotograph.Ifyouareanexperiencedphotographer,youknowthatyoucanfindhighcontrastinanimagewithlow-contrastlightandviceversa.
Contrastisalsodeterminedbysubjectmattercomposition,exposure,anddevelopment.Aseveryoneknows,ascenethatincludesblackandwhite
subjectsislikelytohavemorecontrastthanonewithentirelygrayobjects;butasoftwareLevelsorCurvesadjustmentcanproducehighcontrast,
eveninanentirelygraysceneinvery-low-contrastlighting.
Therelationshipbetweenexposureandcontrastisabitmorecomplex.Increasedanddecreasedexposurecanreducecontrastinanaverage
scene.However,increasingexposurewillincreasecontrastinadarksubject,whereasdecreasingexposuremayincreasecontrastinalightgray
scene.
Wewilltalkabouttherelationshipbetweenlightingandcontrastthroughoutthisbook,andwewillshowhowexposureaffectscontrastinChapter9.
andagridblockstheraysfromallbutanarrowrangeofangles.Inneithercasecanthelightstrikethesubjectfrommany
differentangles.Thismakesalightequippedwithsuchadevicehard,regardlessofitssize.
LIGHTVERSUSLIGHTING
Wehavetalkedaboutthebrightness,color,andcontrastoflight.Thesearealloftheimportantcharacteristicsoflight.
However,wehavesaidverylittleaboutlighting.Indeed,thelittlewehavesaidaboutlightinghasmoretodowiththe
absenceoflight,theshadows,thanwiththelightitself.
Shadowisthepartofthescenethatthelightdoesnotstrike.Highlightistheareailluminated.Wewanttotalkabout
highlight,butwearenotquitereadyforit.Ifyoulookatthetwopepperpictures,youwillseewhy.Thetwophotographs
haveverydifferentlighting,andyoucanseeadifferenceinthehighlightsinthetwopictures.However,thedifferencein
thetwohighlightsisminor;mostviewerswillnoticeonlythedifferenceintheshadow.
Isitpossiblethatlightingdeterminestheappearanceoftheshadow,butnotthehighlight?Figures2.8and2.9prove
otherwise.
TheglassbottlesinFigure2.8wereilluminatedbyasmall,high-contrastlightsource.Figure2.9istheresultofalarge,
softsource.Nowthedifferenceinthehighlightsisobvious.Whydoesthecontrastofthelighthavesuchadramaticeffect
ontheappearanceofthehighlightonthebottlebutalmostnoeffectonthepepper?Asyoulookattheexamples,you
alreadyknowthatthedifferenceinthelightingiscausedbythesubjectitself.
2.8Asmalllightsourceproducessmall,hardhighlightsontheseglassbottles.Comparethesewiththehighlightsinthefollowingphotograph.
2.9Weproducedtheselargehighlightsonthebottlesbyusingalargelightsource.
Photographiclightingismorethanjustlight.Lightingisarelationshipbetweenthelight,thesubject,andtheviewer.Ifwe
wanttosayanymoreaboutlighting,wemusttalkaboutthesubject.
HOWTHESUBJECTAFFECTSLIGHTING
Photonsmove.Photographicsubjectsoftensitstill.Thisiswhywetendtoconsiderlighttobethe“active”playerinthe
photographicevent.Butthisattitudehandicapsourabilityto“see”ascene.
Twoidenticalphotonsstrikingtwodifferentsurfacescanappeardramaticallydifferenttotheeyeandtothecamera.The
subjectchangesthelight,anddifferentsubjectschangethelightindifferentways.Thesubjectplaysanactiverole,justas
thephotondoes.Toperceiveortocontrollighting,wehavetounderstandhowthesubjectdoesthat.
Thesubjectcandothreethingstoaphotonthatstrikesit:itcantransmit,absorb,orreflectthatphoton.
Transmission
Lightthatpassesthroughthesubject,asinFigure2.10,issaidtobetransmitted.Cleanairandclearglassareexamplesof
commonmaterialsthattransmitlight.
Showingyouaphotographoftransmittedlightwouldbeuseless.Asubjectthatonlytransmitsthelightcannotbeseen.
Thesubjectthatdoesnotalterthelightinsomewayisinvisible.Ofthethreebasicinteractionsbetweenthelightandthe
subject,simpletransmissionistheleastsignificantinadiscussionofphotographiclighting.
However,thesimpletransmissionshowninFigure2.10canoccuronlyifthelightstrikesthesurfaceatanangle
perpendiculartoit.Atanyotherangle,thetransmissionofthelighthasaccompanyingrefraction.Refractionisthebending
ofraysoflightastheyaretransmittedfromonematerialtoanother.Somematerialsrefractlightmorethanothers.Air,for
example,refractslightverylittle,whereastheglassusedinacameralensrefractsitagreatdeal.Figure2.11illustratesthe
phenomenon.
Refractioniscausedbyavariationinthespeedoflightcausedbythematerialthroughwhichitistransmitted.(Thespeed
oflightisconstantinavacuum.)ThelightinFigure2.11isslowedasitentersthedenserglass.Thephotonsthatstrikethe
glassfirstarethefirsttohavetheirspeedreduced.Theotherphotons,stillinair,raceahead,causingabendingoftheray.
Thentheraybendsasecondtime,butintheoppositedirection,aseachphotonregainsitsspeeduponexitingbackintothe
air.
2.10Transmittedlight.Clearglassandcleanairarecommonmaterialsthattransmitvisiblelightwell.
IncidentRay
Air
Glass
RefractedRay
2.11Alightraystrikingalight-transmittingmaterialatanyanglebends.Thisbendingiscalledrefraction.Denseglass,suchasthatusedforcameralenses,refractslightespeciallystrongly.
Unlikesimpletransmission,refractioncanbephotographed.Thisisoneofthereasonsthatcompletelytransparentsubjects
arenotinvisible.RefractioncausesthewavyedgeofthemartiniglassinFigure2.12.
2.12Theforegroundglassbottlerefractstheimageofthecocktailglassintheback.
DirectandDiffuseTransmissionSofarwehavetalkedaboutdirecttransmission,inwhichlightpassesthroughamaterialinapredictablepath.Materialssuchaswhiteglassandthinpaperscatterthelightraysinmanyrandom,
unpredictabledirectionsastheypassthrough.Thisiscalleddiffusetransmission(Figure2.13).
Materialsthatproducediffusetransmissionarecalledtranslucenttodistinguishthemfromtransparentmaterials,suchas
clearglass,whichdonotsignificantlydiffusethelight.
2.13Diffusetransmissionisthescatteringoflightpassingthroughatranslucentmaterial.
Diffusetransmissionismoreimportantwhenwetalkaboutlightsourcesthanindiscussingphotographicsubjects.
Coveringasmalllightwithalargetranslucentmaterialisonewaytoincreaseitssizeand,therefore,tosoftenit.A
diffusionsheetinfrontofastrobeandthecloudscoveringthesun,asinFigure2.6,areexamplesoftranslucentmaterials
servingsuchafunction.
Translucentsubjectsareoflittlespecialimportancetophotographersbecausetheirtranslucenceusuallyrequiresnospecial
lightingconsideration.Thisisbecausetheyalwaysabsorbsomeofthelightandreflectsomeofthelight,inadditionto
transmittingit.Absorptionandreflectionarebothmoremajorinfluencesonphotographiclighting.Wewilldealwiththese
next.
Absorption
Lightthatisabsorbedbythesubjectisneveragainseenasvisiblelight.Theabsorbedenergystillexists,butthesubject
emitsitinaninvisibleform,usuallyheat(Figure2.14).
2.14Absorbedlightturnstoheat.Wecanfeelit,butitisnolongervisibletothecamera.
Liketransmission,simpleabsorptioncannotbephotographed.Itis“visible”onlywhenwecompareittootherlightinthe
scenethatisnotabsorbed.Thisiswhyhighlylight-absorbingsubjects,suchasblackvelvetorblackfur,areamongthe
mostdifficultthingstophotograph.
Mostsubjectsabsorbpart,butnotall,ofthelightstrikingthem.Thispartialabsorptionoflightisoneofthefactorsthat
determinewhetherweseeagivensubjectasblack,white,orsomeintermediategray.Anyparticularsubjectwillalso
absorbsomefrequenciesoflightmorethanothers.Thisselectiveabsorptionofcertainlightfrequenciesisoneofthe
factorsdeterminingthecolorofasubject.
Reflection
Reflectionislightstrikingasubjectandbouncingoff.Youknowthatandneednofurtherexplanationfromus.The
conceptiseasybecauseweuseitdaily.Reflectionmakesvisionpossible.Wedonotseeobjects;weseelight.Because
mostobjectsproducenolight,theirvisibilitydependsentirelyonlightreflectedfromthem.Wedonotneedtoshowyoua
photographofreflection.Almostanypictureyouhaveonhandwillservethepurpose.
However,thefamiliarityofreflectiondoesnotmeanthatitneedsnofurtherdiscussion.Onthecontrary,itsimportance
demandsthatwedevotemostofthenextchaptertoit.
3
TheManagementofReflectionandtheFamilyofAngles
Inthepreviouschapterwelookedatlightandhowitbehaves.Welearnedthatthethreemostimportantqualitiesofany
lightsourceareitsbrightness,color,andcontrast.Wealsolearnedthatthesubject,notjustthelight,hasamajorinfluence
onlighting.Asubjectcantransmit,absorb,orreflectthelightthatstrikesit.
Ofthethreewaysthesubjectcanaffectthelighting,reflectionisthemostvisible.Highlytransparentsubjectshave
minimaleffectonlight,sotheytendtobeinvisible.Highlyabsorbentsubjectsmayalsobeinvisiblebecausetheyconvert
lightintootherformsofenergy,suchasheat,whichwecannotsee.
Photographiclighting,therefore,isprimarilyanexerciseinreflectionmanagement.Understandingandmanaging
reflection,fortheresultthephotographerwants,isgoodlighting.Inthissection,wewilllookathowsubjectsreflectlight
andhowtocapitalizeonthosereflections.
Wewillbeginourdiscussionofreflectionwitha“thoughtexperiment.”Wewouldlikeyoutocreatethreedifferent
imagesinyourmind.First,onadesktop,imagineapieceofverythick,perfectlysmooth,graypaper.Thegrayshouldbea
mediumone,lightenoughtowriteonbutdarkenoughthatnoonewouldconfuseitwithwhite.Next,visualizeapieceof
metalofthesamesizeasthepaper.Wesuggestoldpewter.Themetalshouldalsobesmoothandexactlythesamegrayas
thepaper.Third,makeamentalceramictile,veryglossyandthesameshadeofgrayastheothertwosubjects.Finally,put
thethreementalimagestogetheronthesamedeskandexaminethedifferencesyouseeinthethreesubjects.
Noticethatnoneofthesubjectstransmitsanylight.(Thatiswhywemadethepaperthick.)Furthermore,theyallappearto
absorbthesameamountoflight(becausetheyareallthesamegray).Yetthedifferenceinthethreesubjectsisapparent.
Youhaveseenit.(Ifnot,tryagain,andyouwill,nowthatyouknowweexpectyoutodoso!)
Thereasonthatthesesubjects,withidenticaltransmissionandabsorption,appeardifferentisthatthesubjectsreflectthe
lightdifferently.Thereasonyoucanseethedifferenceswithoutlookingatexamplesonthispageisthattheyarepartof
thatvisualknowledgeyoualreadyhaveintheoccipitallobeofyourbrain.
Inthischapter,wearenotgoingtotellyouverymanythingsyourbraindoesnotalreadyknow.Wewill,however,put
someofthatknowledgeintowords.Thiswillmakeiteasyforustotalkaboutreflectionfortherestofthisbook.
TYPESOFREFLECTIONS
Lightcanreflectfromasubjectasdiffusereflection,directreflection,orglare.Mostsurfacescausesomeofeachofthese
threetypes.Theproportionsofeachtypeofreflectionvarywiththesubject,anditistheproportionofeachreflectionin
themixthatmakesonesurfacelookdifferentfromanother.
Wearegoingtoexamineeachofthesetypesofreflectionsinsomedetail.Ineachcase,wewillassumethatthereflection
isaperfectexample,uncontaminatedbyeitheroftheothertwo.Thiswillmakeiteasiertoanalyzeeachofthem.(Events
innaturesometimesoffernearlyperfectexamples.)
Fornow,wedonotcarewhattypeoflightsourcemightbeproducinganyofthefollowingexamples.Onlythereflecting
surfacematters.Anysortoflightcouldwork.
DiffuseReflection
Diffusereflectionsarethesamebrightnessregardlessoftheanglefromwhichweviewthem.Thisisbecausethelight
fromthesourcesisreflectedequallyinalldirectionsbythesurfaceitstrikes.Figure3.1showsadiffusereflection.Initwe
seelightfallingonasmallwhitecard.Threepeoplearepointingtheircamerasatit.
Ifeachoftheseindividualsweretophotographthewhitecard,eachoftheirpictureswouldrecordthesubjectasthesame
brightness.Onfilm,theimageofthecardwouldhavethesamedensityineachnegative.Neithertheangleofillumination
ofthelightsourcenorthe
3.1Awhitecardgivesoffalmostnothingbutdiffusereflection.Becausediffusereflectionfromalightsourceisreflectedequallyinalldirectionsfromthesurface,allthreecamerasseethecardashavingthesamebrightness.
camera’sangleofviewwouldaffectthebrightnessofthesubjectinsuchapicture.
Otherthaninlightingtextbooks,nosurfacesreflectlightinaperfectlydiffusemanner.However,whitepaper
approximatessuchasurface.NowlookatFigure3.2.Noticethatthescenecontainsamostlywhitediagram.
Thereisareasonthatwechosetoputthewhitecircuitdiagraminthisparticularexample.Allwhitethingsproduceagreat
dealofdiffusereflection.Weknowthisbecausetheyappearwhiteregardlessoftheanglefromwhichweviewthem.
(Walkaroundtheroomyouareinnow.Lookatthewhiteobjectsandtheblackobjectsfromdifferentangles.Noticethat
theapparentbrightnessoftheblackobjectsmaychangewithviewpoint,butthewhiteobjectsstayaboutthesame.)
Thecontrastofthelightsourcedoesnotaffecttheappearanceofadiffusereflection.Itisworthprovingthiswithone
morepictureofthe
Photographersdiffusethelightsourcebyreflectingthelightfromanumbrellaorbycoveringitwithatranslucentmaterial.Wecalllightpassing
throughtranslucentmaterialdiffusetransmission.Nowwespeakofdiffusereflection.Thetwoconceptshaveenoughincommonthatweshouldpay
specialattentiontothedifferencesbetweenthem.
3.2Thediagraminthisscenegivesoffprimarilydiffusereflection.Itwouldappearwhitefromanyangle.
Diffusingthelightsourcehasnoeffectonwhetherthereflectionisdiffuse.Rememberthatsmalllightsourcesarealways“hard”(undiffused)and
thatlargelightsourcesarealmostalways“soft”(diffused).ThennoticethatFigures3.2and3.3showdiffusereflectionsproducedbybothdiffused
andundiffusedlightsources.Similarly,Figures3.5and3.6showdirectreflectionsproducedbydiffusedandundiffusedlightsources,asyou’llsee
laterinthechapter.
Theworddiffusionisagoodonebecauseitsmeaningisperfectlyconsistentinbothuses.Ineachcase,itmeansascatteringofthelight.Butwhat
doesthescattering—thelightorthesubject?Thesourcedeterminesthetypeoflight,andthesurfacedeterminesthetypeofreflection.Anylight
canproduceanyreflection,dependingonthesubject.
3.3Thesoftshadowsproveweusedalargelight.Thehighlightsonthediagramlooksimilarbecausethesizeofthelightsourcedoesnotaltertheappearanceofdiffusereflection.
samescene.Asmalllightwasusedfortheearlierphotograph.Wecouldseethatbythehardshadowscastbytheobjects
init.NowlookatFigure3.3toseewhathappenswhenweusealargelightinstead.
Predictably,thelargelightsourcehassoftenedtheshadowsinthescene,butnoticethatthehighlightsonthepaperlook
aboutthesame.ThediffusereflectionfromthesurfaceofthepaperisidenticaltothatinFigure3.2.
Sowenowhaveseenthatneithertheanglenorthesizeofthelightsourceaffectstheappearanceofadiffusereflection.
However,thedistancefromthelighttothesurfaceofthesubjectdoesmatter.Thecloserthelightgetstothesubject,the
brighterthesubjectbecomesand,atagivenexposuresetting,thelighterthesubjectappearsinthefinishedpicture.
Photographerssometimescalldirectreflectionspecularreflection.Asasynonymfordirectreflection,thisisaperfectlygoodterm.Ifyouusethe
wordspecularinthisway,pleasefeelfreetosubstitutethewordsasyoureaddirectreflection.
However,somephotographersalsousespeculartomeansmaller,brighterhighlightswithinalargeone;othersmeanhighlightscreatedbyasmall
lightsource.Directreflectiondoesnotnecessarilyimplyeitherofthese.Becausespecularreflectionhasdifferentmeaningstodifferentpeople,we
willnotusetheterminthisbook.
Modernusageaddsfurtherinconsistency.Originally,specularwasusedtodescribeonlythereflection,notthesourceofthelight.(TheGreekroot
means“mirror.”)Today,somephotographersusespecularlightasasynonymforhardlight,buta“specular”lightsourcedoesnotnecessarily
producea“specular”reflection.Ahardlightisalwayshard,butthewayitreflectsdependsonthesurfaceofthesubject.Sowewillalwayscall
specularlightshardtomakeitclearthatwearetalkingaboutthelight,notthereflection.
TheInverseSquareLaw
Adiffusereflectiongetsbrighterifwemovethelightsourceclosertothesubject.Ifweneeded,wecouldcalculatethis
changeinbrightnesswiththeinversesquarelaw.Theinversesquarelawsaysthatintensityisinverselyproportionaltothe
squareofthedistance.Thus,alightatanyparticulardistancefromthesubjectwilllightthesubjectwithanintensityfour
timesasbrightasthesamelighttwiceasfaraway.Similarly,alightwillhaveninetimestheintensityofthesamelight
movedthreetimesasfarfromthesubject.Astheintensityofthelightfallingonthesubjectvaries,sodoesthatofthe
diffusereflection.
Ignoringthemath,thissimplymeansthatreflectionfromasurfacegetsbrighterifwemovethelightcloseranditgets
dimmerifwemovethelightfartheraway.Intuitively,thisseemsimmediatelyobvious.Whyevenbothertomentionit?
Becausesuchintuitionisoftenmisleading.Somesubjects,asweshallsoonsee,donotproducebrighterreflectionsasthe
lightmovesclosertothem.
DirectReflection
Directreflectionsareamirrorimageofthelightsourcethatproducesthem.Theyarealsocalledspecularreflections.
Figure3.4issimilartoFigure3.1,butthistimewehavereplacedthewhitecardwithasmallmirror.Boththelightsource
andtheobserversareinthesamepositionsastheywereinearlier.
Noticewhathappens.Thistimeoneofthethreecamerasnowseesablindinglybrightreflection,whereastheothersseeno
reflectionatallinthemirror.
3.4Directreflection.Lookingatthemirror,oneofthecamerasseesablindingreflectionofthelightsource,whereastheothersseenoreflectionatall.
Thisdiagramillustratesthedirectreflectionproducedwhenalightisdirectedatapolishedsurfacesuchasglass.Thelight
raysbouncefromthesmoothsurfaceatthesameangleatwhichtheyhitit.Morepreciselystated,theangleofincidence
equalstheangleofreflectance.Thismeansthatthepointatwhichdirectreflectionscanbeseenisexactlydeterminedby
theanglesbetweenthelightsource,thesubject,andthecameraviewpoint.
Sowithallthatinmind,itiseasytounderstandwhythethreecamerasseesuchadifferenceinthebrightnessofthe
mirror.Thosepositionedoneachsidereceivenoreflectedlightrays.Fromtheirviewpoint,themirrorappearsblack.None
oftheraysfromthelightsourceisreflectedintheirdirectionbecausetheyarenotviewingthemirrorfromtheone(and
only)angleinwhichthedirectreflectionofthelightsourcecanhappen.
However,thecamerathatisdirectlyinlinewiththereflectionseesaspotinthemirrorasbrightasthelightsourceitself.
Thisisbecausetheanglefromitspositiontotheglasssurfaceisthesameastheanglefromthelightsourcetotheglass
surface.Again,norealsubjectproducesaperfectdirectreflection.Brightlypolishedmetal,water,orglassmaynearlydo
so,however.
BreakingtheInverseSquareLaw?
Diditalarmyoutoreadthatthecamerathatseesthedirectreflectionwillrecordanimageasbrightasthelightsource?
Howdoweknowhowbrightthedirectreflectionwillbeifwedonotevenknowhowfarawaythelightsourceis?
Wedonotneedtoknowhowfarawaythesourceis.Thebrightnessoftheimageofadirectreflectionisthesame
regardlessofthedistancefromthesource.Thisprincipleseemstostandinflagrantdefianceoftheinversesquarelaw,but
aneasyexperimentwillshowwhyitdoesnot.
Youcanprovethistoyourself,ifyoulike,bypositioningamirrorsothatyoucanseealampreflectedinit.Ifyoumove
themirrorclosertothelamp,itwillbeapparenttoyoureyethatthebrightnessofthelampremainsconstant.
Notice,however,thatthesizeofthereflectionofthelampdoeschange.Thischangeinsizekeepstheinversesquarelaw
frombeingviolated.Ifwemovethelamptohalfthedistance,themirrorwillreflectfourtimesasmuchlight,justasthe
inversesquarelawpredicts,buttheimageofthereflectioncoversfourtimesthearea.Sothatimagestillhasthesame
brightnessinthepicture.Asaconcreteanalogy,ifwespreadfourtimesthebutteronapieceofbreadoffourtimesthe
area,thethicknessofthelayerofbutterstaysthesame.
Nowwewilllookataphotographofthesceneinthepreviousdiagram.Onceagain,wewillbeginwithahigh-contrast
lightsource.Figure3.5hasamirroredsurfaceinsteadoftheearlierdiagram.Hereweseetwoindicationsthatthelight
sourceissmall.Onceagain,theshadowsarehard.Also,wecantellthatthesourceissmallbecausewecanseeitreflected
inthemirroredsurfaceoftheDVD.Becausetheimageofthelightsourceisvisible,wecaneasilyanticipatetheeffectof
anincreaseinthesizeofthelight.Thisallowsustoplanthesizeofthehighlightsonpolishedsurfaces.
NowlookatFigure3.6.Onceagain,thelarge,low-contrastlightsourceproducessoftershadows.Thepictureismore
pleasing,butthatisnottheimportantaspect.Moreimportantisthefactthatthereflectedimageofthelargelightsource
completelyfillstheDVDs.Inotherwords,thelargerlightsourcefillsthefamilyofanglesthatcausesdirectreflection.
Thisfamilyofanglesisoneofthemostusefulconceptsinphotographiclighting.Wewilldiscussthatfamilyindetail.
TheFamilyofAngles
Ourpreviousdiagramshavebeenconcernedwithonlyasinglepointonareflectivesurface.Inreality,however,each
surfaceismadeupofaninfinitenumberofpoints.Aviewerlookingatasurfaceseeseachof
3.5Twocluestellusthispicturewasmadewithasmalllightsource:hardshadowsandthesizeofthereflectionintheDVD.
3.6Alargerlightsoftensshadows.Moreimportant,thereflectionofthelightnowcompletelyfillstheDVDs.Thisisbecausethelightweusedthistimewaslargeenoughtofillthefamilyofanglesthatcausesdirectreflection.
3.7Thelightpositionedwithinthefamilyofangleswillproducedirectreflection.Theotherlight,outsidethefamilyofangles,willnot.
thesepointsataslightlydifferentangle.Takentogether,thesedifferentanglesmakeupthefamilyofanglesthatproduces
directreflection.
Intheory,wecouldalsotalkaboutthefamilyofanglesthatproducesdiffusereflection.However,suchanideawouldbe
meaninglessbecausediffusereflectioncancomefromalightsourceatanyangle.Therefore,whenweusethephrase
familyofangleswewillalwaysmeanthoseanglesthatproducedirectreflection.
Thisfamilyofanglesisimportanttophotographersbecauseitdetermineswhereweshouldplaceourlights.Weknowthat
lightrayswillalwaysreflectfromapolishedsurface,suchasmetalorglass,atthesameangleasthatatwhichtheystrike
it.Sowecaneasilydeterminewherethefamilyofanglesislocated,relativetothecameraandthelightsource.This
allowsustocontrolifandwhereanydirectreflectionwillappearinourpicture.Figure3.7showstheeffectoflights
locatedbothinsideandoutsidethisfamilyofangles.AsyoucanseefromFigure3.7,anylightpositionedwithinthe
familyofangleswillproduceadirectreflection.Alightplacedanywhereelsewillnot.Consequently,anylightpositioned
outsideofthefamilyof
3.8Polarizeddirectreflectionlookslikeunpolarizeddirectreflection,onlydimmer.
angleswillnotlightamirror-likesubjectatall,atleastasfarasthecameracansee.
Photographerssometimeswanttoseedirectreflectionfrommostofthesurfaceofamirror-likesubject.Thisrequiresthat
theyuse(orfindinnature)alightlargeenoughtofillthefamilyofangles.Inotherscenes,theydonotwanttoseeany
directreflectionatallonthesubject.Inthoseinstances,theymustplaceboththecameraandthelightsothatthelight
sourceisnotlocatedwithinthefamilyofangles.Wewillusethisprinciplerepeatedlyinthecomingchapters.
PolarizedDirectReflection
Apolarizeddirectreflectionissosimilartoanordinarydirectreflectionthatphotographersoftentreatthemasthesame.
However,thesereflectionsofferphotographersseveralspecializedtechniquesandtoolsfordealingwiththem.
Likethedirectreflection,onlyoneviewerinFigure3.8willseethereflection.Unlikethedirectreflection,animageofthe
polarizedreflectionisalwayssubstantiallydimmerthanaphotographofthelight
sourceitself.Aperfectlypolarizeddirectreflectionisexactlyhalfasbrightasanunpolarizedone(providedthelight
sourceitselfisnotpolarized).However,becausepolarizationisinevitablyaccompaniedbyabsorption,thereflectionswe
seeinthescenearemorelikelytobemuchdimmerthanthat.
Toseewhypolarizedreflectioncannotbeasbrightasanunpolarizeddirectreflection,weneedtoknowabitabout
polarizedlight.Wehaveseenthattheelectromagneticfieldfluctuatesaroundamovingphoton.Figure3.9representsthis
fluctuatingfieldasajumpropebeingswungbetweentwochildren.Onechildisspinningtheropewhiletheothersimply
holdsit.
Now,let'sputupapicketfencebetweenthechildren,asshowninFigure3.10.Theropenowbouncesupanddown
insteadofswinginginanarc.Thisbouncingroperesemblestheelectromagneticfieldalongthepathofaphotonof
polarizedlight.
Moleculesinapolarizingfilterblocktheoscillationofthelightenergyinonedirection,justasthepicketfencedoestothe
oscillatingenergyofthejumprope.Themolecularstructureofsomereflectingsurfacesalsoblockspartoftheenergyof
thephotoninthesamemanner.Weseesuchaphotonasapolarizedreflectionorglare.Nowsuppose,notbeingsatisfied
witheliminatingjustapartofthechildren'splay,weinstallahorizontalfenceinfrontofthefirst,asshowninFigure3.11.
Withthesecondfenceinplace,ifonechildspinstherope,theotherseesnoropemovementatall.Thecrossedpicket
fencesblockthetransmissionofenergyfromoneendoftheropetotheother.Crossingtheaxesoftwopolarizingfilters
blocksthetransmissionoflight,justasthetwopicketfencesdowithropeenergy.Figure3.12showstheresult.Wherethe
polarizersoverlapwiththeiraxesperpendicular,noneofthetypeisvisibleonthepage.Thetransmissionoflightreflected
fromthepagetothecamerahasbeencompletelyblocked.
Alake,paintedmetal,glossywood,orplasticcanallproducepolarizedreflection.Liketheothertypesofreflections,the
polarizationisnotperfect.Somediffusereflectionandsomeunpolarizeddirectreflectionaremixedwiththeglare.Glossy
subjectsproduceagreateramountofpolarizedreflection,butevenmattesurfacesproduceacertainamount.
Polarizeddirectreflectionismorevisibleifthesubjectisblackortransparent.Blackandtransparentsubjectsdonot
necessarilyproducestrongerdirectreflectionsthanwhiteones.Instead,theyproduceweakerdiffusereflection,makingit
easiertoseethedirectreflection.Thisiswhyyousawthechangeinapparentbrightnessoftheblackobjects,butnotofthe
whiteones,whenyouwalkedaroundyourroomawhileago.
3.9Theoscillatingelectromagneticfieldaroundaphotonrepresentedasajumprope.Thechildontheleftisspinningtheropewhiletheoneontherightholdson.
3.10Whenthechildrenspintheropethroughthepicketfence,itbouncesupanddowninsteadofspinninginanarc.Apolarizingfilterblockstheoscillationoflightenergyinmuchthesameway.
3.11Becausewe’veaddedahorizontalfencetothefirst,whenonechildspinstherope,theotherwillseenomovement.
3.12Theaxesonthetwooverlappingpolarizersareperpendicular.Theyblocklightmuchasthetwofencesdidwiththeenergyofthejumprope.
Glossyblackplasticcanshowusenoughpolarizedreflectiontomakeagoodexample.ThesceneinFigure3.13includesa
blackplasticmaskandafeatheronasheetofglossyblackplastic.Weusedthesamecameraandlightpositionasinthe
picturesofthediagramandmirroredsurface.Youcantellbythesizeofthereflectionsthatweusedalargelightsource.
Boththemaskandtheplasticsheetproducenearlyperfectpolarizedreflection.Fromthisangle,glossyplasticproduces
almostnounpolarizeddirectreflection;blackthingsneverproducemuchdiffusereflection.However,thefeatherbehaves
quitedifferently.Itproducesalmostnothingbutdiffusereflection.
Thelightsourcewaslargeenoughtofillthefamilyofanglesdefinedbytheplasticsheet,creatingdirectreflectionover
theentiresurface.Thesamelightwaslargeenoughtofillonlypartofthefamilyofanglesdefinedbythemask.Weknow
thisbecauseofthehighlightsweseeonlyonthefrontofthemask.
NowlookatFigure3.14.Wemadeitwiththesamearrangementusedinthepreviouspicture,butnowwe’veplaceda
polarizingfilteroverthecameralens.Becausepolarizedreflectionwasalmosttheonlyreflectionfromtheblackplasticin
Figure3.14,andbecausethepolarizingfilterblocksglare,littleofthelightreflectedfromanyoftheblackplasticitems
photographedreachedthecamera.Asaresult,theplasticnowlooksblack.
3.13Theglossyblackplasticsheetandmaskproducealmostnothingbutpolarizeddirectreflection.Thefeathergivesoffalmostnothingbutdiffusereflection.
3.14Apolarizeroverthecameralensblocksthepolarizeddirectreflection.Onlythefeather,whichgivesoffdiffusereflection,iseasilyvisible.
Wedidhavetoopenouraperturebyabouttwostopstocompensatefortheneutraldensityofthepolarizingfilter.Howdo
youknowthatwedidnotaccidentallymiscalculatetheexposure?(Maybewedidsodeliberately,justtogettheimage
darkenoughtoproveourpoint.)Thefeatherprovesthatwedidnot.Thepolarizerdidnotblockthediffusereflectionfrom
thefeather.Sowithaccurateexposurecompensation,thefeatherisaboutthesamelightgrayinbothpictures.
IsItPolarizedReflectionorOrdinaryDirectReflection?
Polarizedandunpolarizeddirectreflectionsoftenhavesimilarappearance.Photographers,outofneedorcuriosity,may
wanttodistinguishonefromtheother.
Weknowthatdirectreflectionappearsasbrightasthelightsource,whereaspolarizeddirectreflectionappearsdimmer.
However,brightnessalonewillnottelluswhichiswhich.Rememberthatrealsubjectsproduceamixtureofreflection
types.Asurfacethatseemstohavepolarizedreflectionmayactuallyhaveweakdirect,plussomediffuse,reflection.
Hereareafewguidelinesthattendtotelluswhetheradirectreflectionispolarized:
•Ifthesurfaceismadeofamaterialthatconductselectricity(metalisthemostcommonexample),itsreflectionislikely
tobeunpolarized.Electricalinsulatorssuchasplastic,glass,andceramicsaremorelikelytoproducepolarizedreflection.
•Ifthesurfacelookslikeamirror—forexample,brightmetal—thereflectionislikelytobesimpledirectreflection,not
glare.
•Ifthesurfacedoesnothaveamirror-likeappearance—forexample,polishedwoodorleather—thereflectionismore
likelytobepolarizedifthecameraisseeingitatanangleof40to50degrees.(Theexactangledependsonthesubject
material.)Atotherangles,thereflectionismorelikelytobeunpolarizeddirectreflection.
•Theconclusivetest,however,istheappearanceofthesubjectthroughapolarizingfilter.Ifthepolarizereliminatesthe
reflection,thenthatreflectionispolarized.If,however,thepolarizerhasnoeffectonthesuspectreflection,thenitis
ordinarydirectreflection.Ifthepolarizerreducesthebrightnessofthereflectionbutdoesnoteliminateit,thenitisa
mixedreflection.
TurningOrdinaryDirectReflectionintoPolarizedReflection
Photographersoftenpreferthatareflectionbepolarizedreflectionsothattheycanmanageitwithapolarizingfilter
mountedontheircamera
Mostphotographersknowthatpolarizerscaneliminatepolarizedreflectiontheydonotwant,butinsomesceneswemaylikethepolarized
reflectionandwantevenmoreofit.Insuchcaseswecanusethepolarizertoeffectivelyincreasethepolarizedreflection.Wedothisbyrotatingthe
polarizingfilter90degreesfromtheorientationthatreducesreflection.Thepolarizedlightthenpassesthrougheasily.
Itisimportanttounderstandthatapolarizeralwaysblockssomeunpolarizedlight.Bydoingthis,ineffect,itbecomesaneutraldensityfilterthat
affectseverythingexceptdirectreflection.Thus,whenweincreasetheexposuretocompensatefortheneutraldensity,thedirectreflection
increasesevenmore.
lens.Ifthereflectionisnotglare,thepolarizeronthelenswillhavenoeffectexcepttoaddneutraldensity.
However,placingapolarizingfilteroverthelightsourcewillturnadirectreflectionintopolarizedreflection.Apolarizer
onthecameralenscanthenmanagethereflectionnicely.
Polarizedlightsourcesarenotrestrictedtostudiolighting.Theopenskyoftenservesasabeautifullyfunctionalpolarized
lightsource.Facingthesubjectfromananglethatreflectsthemostpolarizedpartoftheskycanmakethelenspolarizing
filtereffective.Thisiswhyphotographerssometimesfindpolarizingfiltersusefulonsubjectssuchasbrightmetal,even
thoughthefiltermanufacturermayhavetoldthemthatpolarizershavenoeffectonsuchsubjects.Inthosecases,the
subjectisreflectingapolarizedsource.
APPLYINGTHETHEORY
Excellentrecordingofasubjectrequiresmorethanfocusingthecameraproperlyandexposingthepictureaccurately.The
subjectandthelighthavearelationshipwitheachother.Inagoodphotograph,thelightisappropriatetothesubjectand
thesubjectisappropriatetothelight.
Themeaningofappropriateisthecreativedecisionofthephotographer.Anydecisionthephotographermakesislikelyto
beappropriateifitisguidedbyunderstandingandawarenessofhowthesubjectandthelighttogetherproduceanimage.
Wedecidewhattypeofreflectionisimportanttothesubjectandthencapitalizeonit.Inthestudio,thismeans
manipulatingthelight.Outsidethestudio,itoftenmeansgettingthecameraposition,anticipatingthemovementofthesun
andclouds,waitingfortherighttimeofday,orotherwisefindingthelightthatworks.Ineithercase,thejobiseasierfor
thephotographerwhohaslearnedtoseewhatthelightisdoingandtoimaginewhatitcoulddo.
4
SurfaceAppearances
Allsurfacesproducediffuse,direct,andpolarizedreflectioninvaryingdegrees.Weseeallofthesereflections,butweare
notalwaysconsciousofthem.
Yearsofprogrammingenableourbrainstoedittheimageofthescene.Thiseditingminimizesreflectionthatisdistracting
ortrivialtothesubject.Atthesametime,itmaximizestheimportanceofwhateverlightisessentialtoourcomprehension
ofthescene.Thepsychologicalimageinthebrainmaybequitedifferentfromthephotochemicalonetheeyeactually
sees.
Psychologistshavenotcompletelyexplainedwhythisdifferenceexists.Movementcertainlyhassomethingtodowithit,
butnoteverything.Somevisualdefectsarelessdisturbinginamotionpicturethantheymightbeinastillphotograph,but
notmuch.
Photographersknowthatthebraincannoteditanimageofthesceneaswellasthesceneitself.Wediscoveredthatfact
whenwelearnedhowquicklywecouldspotdefectsinourimages,eventhoughwecouldnotseethematallwhenwe
carefullyexaminedtheoriginalscene.Unconsciouspartsofourbraindidusthe“service”ofeditingthescenetodelete
extraneousandcontradictorydata.Theviewerbecomesfullyconsciousofthesamedetailsuponseeingthepicture.
Howdopicturesrevealdetailswemightneverotherwisenotice?Thisisaquestionforanotherbook.Thisbookisabout
whatweneedtodoaboutthatfactandhowtotakeadvantageofit.Whenwemakeapicturewehavetoconsciouslydo
someoftheeditingthatotherobserversdounconsciously.
THEPHOTOGRAPHERASANEDITOR
Photographiclightingdealsmainlywiththeextremes:thehighlightsandtheshadows.Whenwearehappywiththe
appearanceofthesetwo,wearelikelytobepleasedwiththemiddlerangealso.Highlightandshadowtogetherreveal
form,shape,anddepth.Buthighlightaloneisusuallyenoughtorevealwhatthesurfaceofanobjectislike.Inthischapter
wewillconcernourselvesprimarilywithhighlightandsurface.Mostofourexamplesubjectswillbeflat—two
dimensional,ornearlyso.InChapter5wewillcomplicatemattersabitwiththree-dimensionalsubjectsandamore
detaileddiscussionofshadow.
Inthepreviouschapter,wesawthatallsurfacesproducebothdiffuseanddirectreflectionsandthatsomeofthedirect
reflectionsarepolarized.Butmostsurfacesdonotproduceanevenmixofthesethreetypesofreflections.Somesurfaces
produceagreatdealmoreofonethananother.Thedifferenceintheamountsofeachofthesereflectionsdetermineswhat
makesonesurfacelookdifferentfromanother.
Oneofthefirststepsinlightingasceneistolookatthesubjectanddecidewhatkindofreflectioncausesthesubjectto
appearthewayitdoes.Thenextstepistopositionthelight,thesubject,andthecameratomakethephotographcapitalize
onthattypeofreflectionandminimizetheothers.
Whenwedothiswedecidewhatkindofreflectionwewanttheviewerstosee.Thenweengineertheshottomakesure
theyseethatreflectionandnotothers.
“Positionthelight”and“engineertheshot”implymovinglightstandsaroundastudio,butwedon'tnecessarilymeanthat.
Wedoexactlythesamethingwhenwepickthecameraviewpoint,day,andtimeoutsidethestudio.Wewillusestudio
examplesinthischaptersimplybecausetheyareeasyforustocontroltodemonstratethespecificsclearly.Theprinciples
applytoanytypeofphotography.
Intherestofthischapter,wewillseesomeexamplesofsubjectsthatrequireustocapitalizeoneachofthebasickindsof
reflections.Wewillalsoseewhathappenswhenwephotographreflectionsthatareinappropriatetothosesubjects.
CAPITALIZINGONDIFFUSEREFLECTION
Photographersaresometimesaskedtophotographpaintings,illustrations,orantiquephotographs.Suchcopyworkisone
simpleexampleofacircumstanceinwhichweusuallywantonlydiffuse,andnotdirect,reflection.
Becausethisisthefirstconcretedemonstrationoflightingtechniqueinthisbook,wewilldiscussitingreatdetail.The
exampleshowshowanexperiencedphotographerthinksthroughanylightingarrangement.Beginnerswillbesurprisedat
theamountofthinkinginvolvedinevensuchsimplelighting,buttheyshouldnotbedismayedbyit.Muchofthisthinking
isidenticalfromonepicturetothenext,anditquicklybecomessohabitualthatittakesalmostnotimeoreffort.Youwill
seethisasweprogress,andwewillomitsomeofthedetailinfuturechapters.
Diffusereflectiongivesustheinformationabouthowblackorhowwhitethesubjectis.Theprintedpagesofthisbook
haveblacksandwhitesdeterminedbyareasthatproduceagreatdealofdiffusereflection—thepaper—andthosethat
producelittlediffusereflection—theink.
Becausediffusereflectioncanreflectlightfrequenciesselectively,italsocarriesmostofthecolorinformationaboutthe
subject.Wecouldhaveprintedthispagewithmagentainkonbluepaper(ifthosepickyeditorswouldhaveallowedit),
andyouwouldknowitbecausethediffusereflectionfromthepagewouldtellyou.
Noticethatdiffusereflectiondoesnottellusverymuchaboutwhatthesurfacematerialis.Hadweprintedthispageon
smoothleatherorglossyplasticinsteadofpaper,thediffusereflectionwouldstilllookaboutthesame.(Youcould,
however,tellthedifferenceinmaterialbythedirectreflection.)
Whenwecopyapaintingoranotherphotograph,weareusuallynotinterestedinthetypeofsurfaceonwhichitwas
produced;wewanttoknowaboutthecolorsandvaluesintheoriginalimage.
THEANGLEOFLIGHT
Whatsortoflightingmightaccomplishthis?Toanswerthatquestion,letusbeginbylookingatastandardcopysetupand
atthefamilyofanglesthatproducesdirectreflection.
Figure4.1showsastandardcopycameraarrangement.Thecameraisonastandandisaimedattheoriginalartonacopy
boardbeneathit.Assumethattheheightofthecameraissetsothattheimageoftheoriginalartexactlyfillstheimage
area.
Wehavedrawnthefamilyofanglesfromwhichalight,orlights,canproducedirectreflection.Mostcopyarrangements
usealightoneachsideofthecamera.Weneedonlyonelighttoseetheprinciple.
Suchadiagrammakesiteasytolightthesetup.Onceagain,anylightwithinthefamilyofangleswillproducedirect
reflection,andalightlocatedoutsidethatfamilywillnot.WealsoknowfromChapter3thatalightcanproducediffuse
reflectionfromanyangle.Becausewewantonlydiffusereflection,weplacethelightanywhereoutsidethefamilyof
angles.
4.1Thefamilyofanglesthatproducesdirectreflectionsina“copy”lightingsetup.Thelightinsidethefamilyofangleswillproducedirectreflection;theotherwillnot.Thereisasimilarfamilyofanglesoneachsideofthecamera.
InFigure4.2thecigarboxisphotographedwiththelightplacedoutsideofthefamilyofangles.Weseeonlydiffuse
reflectionfromthesurface,andthetonevaluesinthephotographcloselyapproximatetheoriginal.
Bywayofcontrast,inFigure4.3thelightwasinsidethefamilyofangles.Theresultingdirectreflectioncausesan
unacceptable“hotspot”ontheglossysurface.
Thisisallstraightforwardinthestudioorthelaboratory.However,photographersarealsoaskedtophotographlarge
paintingsinmuseumsorotherlocationsfromwhichtheycannotberemoved.Anyonewhohaseverdonethisknowsthat
museumcuratorsalwaysplacedisplaycases
4.2Inagoodpicture,theboxlabelweseehasnothingbutdiffusereflections(ignoring,fornow,thereflectionfromthegoldfoil),andthetonescloselyresemblethoseintheoriginal.
4.3Placingthelightinsidethefamilyofanglescausedanunacceptablehotspotandobscuredsomeofthedetail.
orpedestalsexactlywherewewanttoputthecamera.Insuchsituations,weneedtoplacethecameraclosertothesubject
thanwemightotherwise.Wethenswitchtoawide-anglelenstogetthewholesubjecttofittheimagearea.
Figure4.4isabird’s-eyeviewofourmuseumsetup.Nowthecamerahasaverywide-anglelenswithabouta90-degree
horizontalangleofview.
Lookwhathashappenedtoourfamilyofangles.Thefamilyofanglescausingdirectreflectionhasgrownmuchlarger,
andtherangeofacceptableanglesforcopylightingismuchsmaller.Thelightnowneedstobemuchfarthertothesideto
avoidunacceptabledirectreflections.
Shootingacopywiththecamerainthispositionwouldyielddrasticallyinferiorresultsifwekeptthelightwherewehadit
inFigure4.1.Thesamelightinganglethatworkswellwhenthecameraisfartherawaycancausedirectreflectionifthe
cameraiscloser.Inthiscase,wewouldhavetomovethelightfarthertotheside.
Finally,noticethatinsomemuseum-likesituations,theshapeoftheroommaymaketheplacementofthelightsmore
difficultthanthatofthecamera.Ifitseemsimpossibletopositionthelightstoavoiddirectreflection,wesometimescan
solvetheproblemjustbymovingthecamerafartherawayfromthesubject(andusingacorrespondinglylongerlensto
obtainalargeenoughimagesize).
4.4Thefamilyofangleshasgrownmuchlargerinthisarrangementusingawide-anglelens.Theresultisasmallrangeofacceptablelightingangles.Onlythelightoutsidethefamilyofangleswillproduceglare-freelighting.
4.5Acopysetupusingalonglens.Becausethefamilyofanglesthatproducesadirectreflectionissmall,findingagoodplacetoputthelightisusuallyeasy.(Hadthewallontherightbeenabitcloser,however,itwouldhavebeguntolimitthelightplacement.Wewilldealwithsuchaproblem
inafewmorepages.)
InFigure4.5,theroomistoonarrowtoalloweasylightplacement,butitisdeepenoughtoallowthecameratobeplaced
atalmostanydistance.Weseethatwhenthecameraisfartherfromthesubject,thefamilyofanglesthatproducesdirect
reflectionissmall.Nowitiseasytofindalightinganglethatavoidsdirectreflection.
THESUCCESSANDFAILUREOFTHEGENERALRULE
Textsthatattemptsimplytodemonstratebasiccopywork(asopposedtogenerallightingprinciples)oftenuseadiagram
similartoFigure4.6torepresentastandardcopysetup.
Noticethatthelightisata45-degreeangletotheoriginal.Thereisnothingmagicaboutsuchanangle.Itisageneralrule
thatusuallyworks—butnotalways.Aswesawinthepreviousexample,ausablelightingangledependsonthedistance
betweenthecameraandthesubjectandtheresultingchoiceoflensfocallength.
4.6The“standard”copysetupsometimesproducesgoodresultsandsometimesdoesnot.Ausablelightingangledependsalsoonthedistancebetweenthecameraandsubjectandthechoiceoflensfocallength.
Moreimportant,weneedtonoticethatthisrulemayfailtoproducegoodlightingifwedonotgiveattentiontothe
distancebetweenthelightandthesubject.Toseewhy,wewillcombinetheprincipleinFigure4.1withthatofFigure4.6.
InFigure4.7,weseetwopossiblelightpositions.Bothlightsareata45-degreeangletothesubject,butonlyoneofthem
willproduceacceptablelighting.Thelightthatisclosertothesubjectiswithinthefamilyofanglesthatproducesdirect
reflectionandwillcauseahotspotonthesurface.Theotherlightisfarenoughawaytobeoutsidethefamilyofangles
andwillilluminatethesurfacenicely.
Soweseethatthe45-degreerulewillworkfineifthephotographergetsthelightsfarenoughawayfromthesubject
surface.Infact,theruleoftendoesservewellbecausephotographersgenerallydomovethelightsfartherawayfromthe
subjectforyetanotherreason,toobtainevenillumination.
4.7Theimportanceofthedistancefromthelighttothesubject.Bothofthelightsshownareat45degreestothecenterofthesubject,butonlyoneissatisfactory.Thelightinsidethefamilyofangleswillproducedirectreflection.
THEDISTANCEOFLIGHT
Uptonowwe’veonlyconsideredtheangleofthelight,notitsdistance.Butclearlythat’simportanttoo,becauseweknow
thatdiffusereflectionsgetbrighterasthelightgetsclosertothereflectingsurface.Figure4.8revisitsanearlier
arrangement,nowemphasizingthedistanceofthelight.
Onceagain,weareusingawide-anglelenstophotographthesubject.Rememberingthatsuchsituationsleaveavery
smallrangeofanglesofilluminationthatdonotcausedirectreflection,wehavepositionedthelightataveryshallow
angletothesurface.Buttheedgeofthesubjectthatisclosertothelightreceivessomuchmorelightthantheedgefarther
awaythatuniformexposureisimpossible.
Figure4.9showstheresultingexposure.Theshallowlightingangleavoidsdirectreflection,butthediffusereflectionon
onesideoftheimageissobrightthattheconsequencesarealmostasbad.
4.8Theshallowanglethatavoidsdirectreflectionisalsomorelikelytocauseunevenilluminationifwedon’ttakecaretoavoidit.
4.9ApossibleconsequenceofthesituationshowninFigure4.8.Althoughthelightplacementavoideddirectreflection,theilluminationistoouneventopreservedetailonboththeleftandrightsides.
Obviously,asecondlightontheothersideofthesubjectwouldhelpprovidemoreevenillumination.(Thisisexactlywhy
mostcopysetupsdo,indeed,usetwolights.)Withextremelyshallowlightingangles,however,thesecondlightstilldoes
notprovideuniformexposure.Wesimplygettwooverexposedareasinsteadofone,withadarkareainthecenter.
Onesolutiontothisproblemistomovethelightclosertothecamera.(Anextremeexampleofthisisaflashmounted
directlyonthecamera.)Thenthelightisroughlythesamedistancefromallpointsonthesurface,andtheilluminationis
moreeven.Butthissolutionisalsolikelytoplacethelightinthefamilyofanglesthatcausedirectreflection,whichisa
worseproblem.
Theonlysolutiontothisproblemthatalwaysworksistomovethelightfartherawayfromthesubject.Intheory,alight
thatisaninfinitedistanceawaywillproduceexactlyequallybrightdiffusereflectionsatallpointsonthesurface,evenat
themostshallowangle.Unfortunately,alightaninfinitedistanceawayisalsolikelytobeinfinitelydim.(Wewillnot
evenbegintodealwiththeproblemsoffindingalightstandthathigh.)
Inpractice,wedonotusuallyneedtogetthelightquitethatfarawaytoobtainsatisfactoryresults.Wejustneedtogetthe
lightfarenoughfromthesubjecttoproduceacceptablyevenillumination,butweneedtokeepitcloseenoughfor
acceptablyshortexposuretimes.
Wecouldofferyoumathematicalformulastocalculateanacceptabledistancebetweenthelightandthesubjectatany
givenangle(andforanygivenacceptableside-to-sideexposureerror),butyouwouldnotusetheformulasbecauseyoudo
notneedthem.Thehumaneyeisgoodatjudgingtheacceptablecompromisedistance,providedthephotographerisaware
ofthepotentialproblemfromthestart.Placethelightssothattheilluminationlooksreasonablyeven;thendouble-check
thatjudgmentbymeasuringvariouspointsonthesurfacewithalightmeter.
DOINGTHEIMPOSSIBLE
Theprecedingexamplestellusthatevenilluminationandglare-freeilluminationcanbemutuallyexclusivegoals.The
closerthelightsourceistothecamera,themoredirectlyitlightsthesubjectandthemoreeventheilluminationbecomes.
However,thefartherthelightistotheside,thelesslikelyitistobewithinthefamilyofanglesthatcausesdirect
reflection.
Wehavealsoseenthattheusualsolutiontothisdilemmarequiresmoreworkingspaceinanydirection.Hereiswhy:
•Movingthelightsclosertothecameraaxis,forexample,meansmovingthecamerafartherawayfromthesubject(and
usingacorrespondinglylongerlenstogetasimilarimagesize).Thiscreatesasmallerfamilyofanglesthatcausesdirect
reflectionsandallowsmorefreedominchoosingtheangletolightthesubject.
•Conversely,ifcircumstancesdictatethatthecamerabeveryclosetothesubject,wemustlightthesubjectatavery
shallowangletokeepthelightsourceoutsidethefamilyofangles.Wemustthenplacethelightsmuchfartherfromthe
subjecttoachieveevenillumination.
Unfortunately,wesometimeslacktheworkingspaceweneedforeitherofthesesolutions.Aphotographermayhaveto
photographararedocumentinastorageareasofilledwithfilingcabinetsthatthereisalmostnoroomtowork.Evenina
galleryarea,theremaynotbeenoughfloorspacetoproperlylightareallylargepainting.
Figure4.10showssuchan“impossible”lightingproblem.Thecameracouldbeonatripodaimedatadocumentonthe
floor,the
4.10An“impossible”lightingsituation:wecannotpositionthecameraandlightstoprovideuniform,glare-freeillumination.
obstaclesonthesidescouldbefilingcabinets,andtheceilingcouldsettherestrictiononcameraheight.Orthecamera
couldbefocusedonan8-by-10-footpaintingonawallwithotherwallsordisplaycasespresentingtheobstacles.Either
way,wecannotpositionthecameraandlightstoprovideilluminationthatisbothuniformandglare-free.
Ataglancewepredictthatthephotographmadewithsuchanarrangementisuseless.Figure4.11confirmstheprediction.
Thesolutioniseasywhenwerememberthat(1)the“glare”weseeonthesurfaceoftheoriginalisamixtureofdirectand
diffusereflection,and(2)apolarizingfilteronthelenscaneliminatepolarizeddirectreflection.
4.11Oneresultofthe“impossible”situationshowninFigure4.10.Thispictureis,asyoucanclearlysee,useless.Becauseofthewayinwhichwewereforcedtosetupourlights,theoriginalwaspartiallyobliteratedbythedirectreflectionfromitssurface.
4.12Thesolutiontothe“impossible”lightingrequiresplacingthelightsforevenilluminationandusingpolarizerstopreventglare.Theaxisofthelightpolarizerpointstothecamera;theaxisofthelenspolarizerisperpendiculartothat.
Figure4.12showshow.Wefirstpositionthelightsforevenillumination,withoutconcernaboutwhetherwearecreating
directreflection.Thenweplacepolarizingfiltersoverthelightswiththeiraxesorientedtowardthecamera.Thisassures
usthatthedirectreflectionispolarized.Next,apolarizingfilteronthecamera,withitsaxisoriented90degreestothose
onthelights,eliminatesthatpolarizeddirectreflection.
Intheory,thisarrangementallowsthecameratoseeonlythediffusereflection.Inpractice,wemaystillseesome
polarizedreflectionbecausenopolarizingfilterisperfect.However,thedefectisnegligibleinallbuttheworstcases.
Figure4.13provesit.Neitherthecameranorthelighthasbeenmoved,buttheimprovementisdramatic.
4.13Agoodphotographdespite“impossible”circumstances,usingthesolutionfromFigure4.12.ThispictureshowsthesamesubjectlitbythesamelightinthesamepositionasinFigure4.11.Comparethetwopictures.
Polarizingthelightsourcehasseriousdrawbacksandisasolutiontoavoidwheneverpossible.Fortunately,understandingandcontrollingthesize
andangleofthelightsourcemakespolarizingthelightsourceitselfunnecessaryinmostsituations.Somephotographersgoforyearswithout
needingtouselight-polarizingfilters.
Wehavedeliberatelyconceivedthe“impossible”copyproblemtobeoneofthoserarecasesinwhichpolarizingthelightistheonlysolutiontothe
problem.Photographerswhosespecialtyroutinelyrequireshighlycontrolledlightingwilloccasionallyencounterthesecases.Becauseawarenessof
aproblemisthefirststeptowardthesolutionoftheproblem,wewanttolistthepossibledifficultiesnow.
Intheory,thecombinedeffectofa“perfect”polarizingfilteronthelightandanotheronthelensshouldcostatotaloftwostopsofexposure.Real
polarizersarefarfromperfect,though.Inpractice,becausepolarizershavealotofneutraldensity,theactualexposurereductionislikelytobefour
tosixstops.
(Continued)
65
Theproblemgetsevenworseinnoncopysituations,wherewearelikelytoloseadditionallightthroughdiffusionmaterials.Theconsequentaperture
maybetoowidetomaintainadequatedepthoffield,ortheexposuremaybesolongthatreciprocityfailurebecomesdifficulttocalculateand
cameraorsubjectmovementisincreasinglydifficulttoavoid.
Theidealsolutiontothisproblemistousethemostpowerfullightsthatourbudgetandtheavailableelectricalcurrentallow.Ifthatisnotenough,
wetreattheproblemaswewouldanyotherlow-light-levelscene:weuseacamerasupportthatisassturdyaspossibleandfocusthecameraas
carefullyaspossibletomakemaximumuseofwhatlittledepthoffieldwehave.
Thesecondproblemisthatpolarizingfiltersarevulnerabletodamagebyheat.Rememberthatthelightabsorbedbythepolarizersdoesnotsimply
disappear.Itturnsintoheatandthreatenstocookthings!
Photographersusingstrobesoftenleavethepolarizersoffthelightsuntiltheyarereadytoshoot.Theyturnoffthemodelinglightsbeforeattaching
thepolarizingfilters.Thebriefflashoftheflashtubepresentsminimalheatdanger.
Polarizingfiltersusedwithincandescentlightsneedtobeattachedtoabracketoraseparatelightstandadistanceawayfromthelight.Theexact
distancedependsonthewattageandthereflectordesignofthelight.Itisworthcuttingasmallpieceofthepolarizingmaterialanddeliberately
burningitinfrontofthelighttodetermineasafedistance.
Finally,wemustrememberthatpolarizingfilterscanhaveaminoreffectoncolorbalance.Ifyouareshootingfilmandcan’tadjustthecolorbalance
inthecamera,itiswisetoshootandprocessacolortestandadjustthecolor-compensating(CC)filtrationbeforeexposingthefinalfilm.
USINGDIFFUSEREFLECTIONANDSHADOWTOREVEALTEXTURE
Inanydiscussionofsurfacedefinition,wemusttalkabouttexture.(Thisiswhywepromisedatthebeginningofthis
chapterthatallexampleswouldbenearlytwo-dimensional.)Wewillfirstlookataphotographthatfailstorevealthe
textureofthesubject.Thiswillhelpusanalyzetheproblemandcomeupwithabettersolution.
Wephotographedthedetailontheglove’ssurfaceshowninFigure4.14withaportablestrobemountedonthecamera.If
theobjectistoshowtexture,thepictureisdecidedlyunsatisfactory.
Thelightcoloroftheglovecontributestotheproblem.Weknowthatalllightsubjectsproducediffusereflections,andwe
knowthatthebrightnessofaperfectdiffusereflectiondoesnotdependontheangleofillumination.Forthisreason,light
strikingthesideofaparticleoftexturereflectsbacktothecameraalmostasbrightlyaslightstrikingthetopofthe
particle.
Thesolutionistomovethelighttoaveryshallowangletothesurfacesothatitskimsacross,asseeninFigure4.15.This
giveseachparticleoftextureahighlightsideandashadowside.
Noticethatthisarrangementmayproduceunevenillumination,justasitdidwhenwemovedthelighttoashallowangle
inthecopysetup
4.14Aglovephotographedwiththelightmountedonthecamera.Withnocontrastinghighlightsandshadows,muchoftheglove’ssurfacedetailisinvisible.
4.15Asmalllightataverylowangletothesubjectproducesthecontrastinghighlightsandshadowsneededtorevealtextureinmedium-andlight-tonedsubjects.
4.16ThesamegloveweusedinFigure4.14.OnlythistimewephotographeditwithrakinglightsuchasshowninFigure4.15.
inFigure4.8.Thesolutionisthesame:movethelightfartherfromthesubject.
Thetextureinthistypeofsurfacecanbehelpedstillmoreifweuseassmallalightsourceaspossible.Thisisbecause
smalllightsourcesproducesharplydefinedshadows.
Iftheparticlesoftexturearetiny,theirimagemaybetoosmalltoresolvesharply.Iftheshadowitselfisassharpas
possible,thentheimageoftheshadowismorelikelytosurvivetheopticallimitations.Figure4.16istheresult.
Lightingfortextureinthismannerissoeasytounderstandthatitisalmostintuitive.Novicephotographerssoonerorlater
learnthiswithnohelpfromus.Wearenottryingtopointouttheobvious.Instead,wewanttocontrastthelightingofthis
clothwithanother,lessobvious,exampleinwhichthesametechniquedoesnotworkatall.
CAPITALIZINGONDIRECTREFLECTION
Figure4.17wasproducedbythesamelightingasthesuccessfulphotographoftheleatherglove’stexturethatyousawin
Figure4.16.Itshowshowapplyingagoodtechniqueatthewrongtimecanproduceabadpicture.Thelightingthat
revealedthetexturesowellinthegloveloses
4.17Thesamelightingthatrevealedtextureinthebrownglovelosesmostofthedetailintheblackleatherbookcover.
almostalldetailinthenotebook'scover.Youhavetotakeourwordthatthetextureexists.
Therakinglightweusedonthelight-browngloverevealeddetailbyplacingashadowononesideofeachparticleof
textureandadiffusehighlightontheotherside.Thesameshadowexistsononesideofeachparticleoftextureinthe
blackleathernotebookcover(althoughyoucannotseeit),butthediffusehighlightontheothersideofeachparticleis
gone.Theproblemwiththisphotographiscausedbythesubjectitself.Itisblack,andblacksubjects,bydefinition,
producelittlediffusereflection.
Weknowthatincreasingexposurewouldenabletheweakdiffusereflectionsontheleathertorecord,butanexposure
increaseisrarelyanavailableoptionbecauseimportantlight-tonedareasalsoexistin
mostscenes.Ifweincreasedtheexposure,thehighlightdetailinthelightersubjectmattermightbehopelesslylost.
Besides,thisisabookaboutlighting,andwearehonorboundtodealwiththeproblemswithoutexposuremodification,
usinglightingtechniquealone.
Ifwecannotgetsignificantdiffusereflectionfromtheleathersurface,wewilltrytoproducedirectreflectioninstead.This
seemstobeouronlyremainingoption.Becausedirectreflectioncanonlybeproducedbylightcomingfromalimited
familyofangles,ourfirststepistoseewherethatfamilyofanglesmightbe.
Figure4.18showswherethelightmustbeifthecameraistoseedirectreflectiononthesurface.Furthermore,toproduce
directreflectionacrosstheentiresurface,thelightmustbelargeenoughtocompletelyfillthisfamilyofangles.Therefore,
weneedalightofatleastthesizeandinthepositionshowninthediagram.Thelightsourceforthispicturecouldbean
overcastsky,asoftbox,orareflectorcardilluminatedbystillanotherlightsource.Allthatmattersisthatthelightbethe
rightsizeandintherightplace.
Noticethatthisarrangementcouldnotbemoredifferentfromtheonethatworkedwellforthewhitecloth.Insteadof
rakingthelight
Large
Light
FamilyofAnglesDefinedbyCameraPositionandSizeofSubject
GlossyBlackSubject
70
4.18Alightfillingthefamilyofanglesdefinedbytheblackleatherbook.
fromtheside,wehaveputitabovethesubject.Thisnearlyeliminatesthesmallshadowsthatdefinedtheclothtexture.
Insteadofasmalllightsource,wehavealargeone.Thismeansthatwhateverslightshadowsdoremaininthetexturewill
betoosofttodefinethetextureclearly.
Inotherwords,thetheorythatpredictsthebestwaytolighttheclothalsosaysthatournewlightingarrangementisthe
worstpossiblewaytolighttheleather!Thisapparentcontradictioniscausedbytheearliertheoryneglectingone
consideration:directreflection.
ThelargelightabovethetableproducesthemagnificenttexturevisibleinFigure4.19.Noexposureincreasewas
necessary.TheamountoflightfallingontheleatheristhesameasthatinFigure4.17.Nevertheless,thehighlightinthe
leathertexturehasmovedupthetonalscalefromnearblacktomiddlegray.
4.19UsingthelightingdiagrammedinFigure4.18maximizesdirectreflectionandrevealstextureintheleather.
Theapparentincreaseinilluminationcomesfromgoodreflectionmanagement.Theleathersurfacecanproducelittle
diffusereflectionbutagreatdealofdirectreflection.Bycapitalizingonthetypeofreflectionappropriatetothesurface,
wehaverecordedthesubjectaswellaspossible.
COMPETINGSURFACES
Photographerswouldhavelessgrayhair,andlessincome,ifallworkwereaseasyastheexampleswehaveseensofarin
thischapter.Somesurfacesarerenderedbetterbycapitalizingondiffusereflection;othersaredepictedbestby
capitalizingondirectreflection.We’veseenthatthebestlightingforonecanbetheworstfortheother.Whenwehave
bothinasinglescene,ourjobgetsharder.
Toooften,however,tobecompletelylegible,somepartsofthescenerequirediffusereflection,whereasothersneeddirect
reflection.Inmanyofthesecases,wecansimplydealwiththemoreimportantpartofthescene.Ifwegetthatright,
viewersdonotnoticeminordefectsinthelightingoftherestofthesurface.Onotheroccasions,however,severalentirely
differentpartsofthesurfaceareallimportant,andthosedifferentpartsofthepictureabsolutelymusthavedifferent
lighting.
Thisdoesnotrequireanynewprinciples.Itdoesmeanthatwehavetoapplymorethanoneprincipletolightasingle
scene.Aswesawinthephotographsofthewhiteclothandtheblackleather,thetechniquethatproducesoneeffectoften
excludesanother.Inextremecases,thismeansthattheproblemspresentedbycompetingsurfacescan’tbesolved.When
thathappens,weshootmorethanonepicture,eachlitdifferently,andthenwecombinethemdigitally.Whethertogetthe
picturerightinthefirstplaceortofixitlaterisentirelyamatterofchoosing,onacase-by-casebasis,whatevertakesless
time.
Commercialphotographerssometimesworkoutthecompositionofaphotographbeforebeginningtoperfectthelighting.
Afterall,iftherelationshipoftheanglesbetweenthelight,thesubject,andthecameraiscritical,itmakesnosenseto
carefullypositionthelightbeforeknowingtheorientationofthesubject.
Figure4.20isonesuchpreliminarycomposition.Onesmalllighttotherightofthecamerailluminatesthiscollectionof
surfaces.Thepositionofthelightissimilartothesingle-lightcopysetupshowninFigure4.1.Fornow,theonlypurpose
ofthatlightistolightthesubjectwellenoughtoseeitinthecamera.
Beforelightingascenewell,wehavetodecidewhatisimportantinit.Thispictureisintendedtoproduceinterestina
musicCDscheduledtobereleased.Almostanyadvertisingimageneedstocarrythemessageasstronglyaspossibleand
asindependentlyofthetextaspossible.
4.20Litbyonesmalllighttotherightofthecamera,thisphotographwasexposedonlybydiffusereflection.
(Areadermaycontinueturningpageswithoutbotheringtoreadthecopyifthephotograph,byitself,doesnotcreate
enoughinterestintheproduct.)Withthatinmind,thisphotographmustmakethediscanditspackagingimmediately
visible.Atthesametime,thestick-onlabelisessentialtotheadconcept.
Oftheimportantcompetingsurfaces,onlythetypeonthelabelisadequatelyrecordedinthefirstphotograph.Wewould
expectthatbecausethelightingresemblescopylightingandthereisnotechnicaldifferencebetweenphotographingalabel
andcopyingapainting.Buttheblackdiscinitsblackenvelopeandblackcasedoesnothaveenoughshadowdetailto
surviveeventhereasonablygoodreproductioninthisbook.Hadthisshotbeenusedfortheintendedadinatrade
newsletter,onnewsprintpaper,theresultwouldhavebeenevenworse.
4.21Directreflectionaloneproducesgooddetailintheblacksubjects,buttheblacktypeonthelabelistooweak.
Becausethetestshotsuffersfromthesameproblemswesawintheblackleather,wedecidedtotrythesamesolution
diagrammedearlierinFigure4.18.Weusedalightlargeenoughandpositionedtomaximizethedirectreflectiononthe
blacksurfaces.
Figure4.21istheresult.Predictably,thedetailintheblackdiscandpackagingaregood.Equallypredictable,thedirect
reflectionthatbrightenstheblackplastichasthesameeffectontheblacktypeinthelabel.Thetypeistooweaktolook
good.Unlessyoureyesaregood,itisnotevenlegible.
Thus,eachbasiclightingtechniqueisgoodforonetypeofsurfacebutbadfortheother.Still,bothsurfacesareimportant.
Thiscomplicateslifeconsiderably.Fortunately,severalpossiblesolutionsareavailable.Wewillpresentfourofthemore
promisingones.
TryaLensPolarizingFilter
Trythissolutionfirst;it’stheleastlikelytowork,butit'stheeasiest.Onsomesurfaces,thedirectreflectionwedonot
wantwillturnouttobepolarizeddirectreflection.Ifthisisthecase,wecaneliminatetheoffendingreflectionwitha
polarizingfilteronthelens.Ifwearelucky,thedirectreflectionwewanttokeepwillbeunpolarizedandwillnotbe
significantlyaffectedbythefilter.
Morelikely,however,thedirectreflectionwillbepolarizedonbothsurfacesoronneither.Soifthepolarizereliminates
theundesirablereflection,italsofiltersoutthedirectreflectionwedolike.
UseaStillLargerLight
Figure4.22showsalightlargeenoughtofillthefamilyofanglescausingdirectreflection,plusalargerangeofangles
thatdonot.Thelightcomingfromthefamilyofanglescausingdirectreflectionlightsthe
4.22Thislightsourceismuchlargerthanthatneededtofillthefamilyofanglesthatcausesdirectreflection.
blackplasticwell.Therestoftheraysfromthissourcestrikethesurfacefromanglesthatcanonlyproducediffuse
reflectionand,therefore,lightthelabelwell.
Thissolutionisespeciallyeffectiveusingalight,plusanindependentlysupporteddiffusionsheet,ratherthanasoftbox.
Thenwecanlightonepartofthediffusionsheetmorebrightlythananothertoplaceslightlymoredirectreflectiononthe
blackplasticthanonthelabel.
Unfortunately,thisapproachisacompromise,notacompletesolution.Thetypewillnotbequiteasblackasitwasinthe
firstphotographofthisscene,andtheplasticswillnothaveasmuchdetailastheydidinthesecondpicture.Bothtypesof
surfacesmightbelitadequatelybutnotaswellaspossible.
UseMoreThanOneLight
WecouldalsocombinethelightingusedinFigure4.20withthatinFigure4.21.Suchatwo-lightarrangementisshownin
Figure4.23.Inprinciple,thissolutionisthesameasusingasingleverylargelight:some
4.23Thelargelightproducesdirectreflection,whereasthesmallonenearthecameraproducesonlydiffusereflection.Theresultisacompromise.
oftherayscomefromanglesthatcausedirectreflection,whereasotherscomefromanglesthatcanonlycausediffuse
reflection.Usingtwolightsmaybeeasiertocontrol,however,becausewecanadjustthepowerineachlight
independently.
Likeasingleverylargesource,themultiple-lightsolutionisalsoacompromise.It'sabettercompromise,butneitherthe
diffusereflectionnorthedirectreflectionwilllookasgoodasitmightifwehadtolightforonlyoneofthetwo.
Thesizeofthesubjectoftendetermineswhethertousemultiplelightsorasingleverylargeone.Allotherthingsbeing
equal,smartphotographersdowhateverrequirestheleastwork.Inthiscase,itiseasytocomeupwithasinglesourcethat
isverylargecomparedwiththesizeofthesubject.Ifthesubjectwerelarger,itmightbeeasiertousetwolights.
UseaGobo
Wehavebeencarefultopointoutthattheprecedingtechniquesarecompromises.Theyworkformany,butnotall,
competingsurfaces.
Ifthestick-onlabelisnotveryglossy,andifweknowthephotographisgoingtobewellreproduced,thecompromiseis
oftenadequate.Ifthelabelisglossy,however,noneofthelightingsolutionswehaveseensofarwillbeadequate.Ifthere
isenoughdirectreflectionfortheblacksurfaces,therewillbetoomuchdirectreflectiononthelabel.Furthermore,ifthe
advertisementistobeusedinanewspaperorprintedonotherinferiorpaper,thedefectismagnified.
Theonlyremedyforthisproblemisasmallgobothatfillsthefamilyofanglesthatcausesdirectreflectiononthelabelbut
thatisnotlargeenoughtoextendintothefamilyofanglesthatproducesdirectreflectionontherestofthesubject.(Gobo
isphotospeakforanythingthatgoesbetweenthesubjectandthelightsourcespecificallytoblockpartofthelight.)Figure
4.24showsthepositionandsizeofagobothatcouldaccomplishthis.
Althoughthegoboislargeenoughtoblockalldirectreflectiononthelabel,noticeinthediagramthatitdoesnotblock
muchofthetotalsurfaceofthelightsource.Westillobtainalotoflightfromthoseanglesthatcausediffusereflectionon
thelabel.Therefore,thetotalexposureisnotsignificantlyaffected.
Gettingthegobotobetherightsizeandattherightdistanceisnotalwayseasy.Noticethatthecloserthegoboistothe
lightsource,thelargeritneedstobetofillthesamefamilyofangles;also,thelargerthegobois,themoreitblocksthe
totalilluminationandthemorelikelyitistoaffectexposure.Thisseemstosuggestthatwemightwantthegoboasclose
tothesubjectaspossiblesothatasmalleronewilldothejob.
4.24Thesmallgoboblocksthefamilyofanglesthatcausesadirectreflectiononthelabelbutnottheonethatcausesdirectreflectionontherestofthesubject.
Butagoboclosertothesubjectismorelikelytocastavisibleshadowonthetabletop.Thisisbecausemovingthegobo
fartherfromthelightmakesthelighteffectivelysmallercomparedwiththegobo.Becausesmallerlightsourcesproduce
hardershadows,wearemorelikelytobeabletoseetheshadow.
Sothegoboneedstobefarenoughfromthesubjecttoavoidcastingavisibleshadow,yetfarenoughfromthelighttobe
smallenoughtoblockaslittletotalilluminationaspossible.Italsoneedstobeexactlylargeenoughtoblockthedirect
reflectiononthelabelbutnotontherestofthesubject.Thisiswhywesavedthegoboforthelastsolutiontothe
competing-surfacesexercise.Itisthemosteffectivesolution,butitrequiresthemostworkandthemosttime.Onthefirst
occasionyouattemptit,youmayfindpositioningthegobowithprecisiontobeabittedious.Fortunately,itsoongets
easierwithalittlepractice.
Wecanusuallysupportthegoboonathinwoodendowelclampedtoanearbylightstand.Thisarrangementprovides
plentyoffreedomtomovethegoboinanydirectionuntilwegetitright.However,ifanythinginthesceneismirror-like,
thenthewoodensupportbecomesa
4.25TheresultofthetechniqueillustratedinFigure4.24:detailintheblacks,pluslegibletypeonthelabel.
visiblereflectioninthepicture.Inthosecases,wetapethegobodirectlytothediffusionmaterialabovethesubject.Then
wecanmovethelightitselfuntilthegoboisproperlypositioned.
Figure4.25istheresultofthisarrangement.Thedirectreflectionisgonefromthelabelbutnotfromthediscorits
packaging.
COMPLEXSURFACES
Inthisbookwewillusethetermcomplexsurfacetomeanasinglesurfacethatrequiresbothdiffuseanddirectreflection
todefineitproperly.Glossywoodisagoodexample.Onlydirectreflectioncantelltheviewerthatthewoodisglossy,but
diffusereflectionisessentialtorevealthecolorandthegrainofthewoodbeneaththegloss.
Figure4.26isapieceofhighlypolishedwoodlittoproducebothdirectanddiffusereflection.Amedium-sizedlight
sourcehasbeen
4.26Directreflectionintheleftofthesceneshowsthegloss,whereasdiffusereflectionattherightrevealsthewoodgrain.
positionedtoreflectinthelowerportionofthewoodensurfacetoshowtheglossyfinish.Noticethattheslightphysical
textureinthesurfaceisalsorevealedbythedirectreflection.
Thelightwaslargeenoughthatitfilledtheentirefamilyofanglesrequiredtoproducedirectreflectionoverthewhole
surface.However,weblockedpartofthelightwithagobosothattherightpartofthesurfaceproducesonlydiffuse
reflection,whichallowsustoseethecolorandgrainstructureinthewood.Noticethattherightareaistheonlyareain
whichthetruecolorofthewoodwouldbeclearlyapparent.Figure4.27diagramsthelightingmethod.
Noticeespeciallythetransitionzonebetweentheareasofdiffuseanddirectreflection.Thisareahassomeofeachtypeof
reflection,whichoftenrevealsthesurfacebetterthaneitherdiffuseordirect
4.27Lightingtoproduceboththedirectandthediffusereflections,usedtoilluminatethewoodboxinFigure4.26.
reflectionalone.Ifyouwanttocapitalizeonthiseffect,youcanenlargethetransitionzonetofillmoreofthesurface.Just
movethecamerafartherfromthesubjectandusealongerlenstokeepthesubjectasimilarsize,ormovethegobocloser
tothelightsothatitcastsasoftershadowonthediffusionmaterial.
Finally,seehowmucheasierthisexercisebecomesifwedonotrestrictourselvestoatwo-dimensionalsurface.Lookat
whathappensinFigure4.28ifweputathree-dimensionalobjectonthewoodsurface.Thereflectionoftheglassesinthe
woodtellstheviewerthatthewoodisglossy.Addingasecondarysubjectrevealsthewoodbetterthanwearelikelytobe
abletorenderthewoodalone.
4.28Theglassesaddathree-dimensionalelement,whichprovidesadditionalvisualclues(thereflectionoftheglasses)toprovethesurfaceisglossy.
Addingathree-dimensionalsubjecttothiskindofsceneoftenmakesthelightingeasier.Wecannotpursuethisapproach
veryfar,however,becausewepromisedthatthischapterwouldbeabouttwo-dimensionalandnearlytwo-dimensional
subjects.Inthenextchapterwewillseewhathappenswhenthosesurfacesfacethreedifferentdirectionsatonce.
5
RevealingShapeandContour
Inthepreviouschapter,wedealtwiththeproblemsandopportunitiesforlightingobjectsthatareflat,ornearlyso—things
thatarevisuallydefinedonlyintermsoflengthandwidth.Inthischapterweaddthethirddimension—depth.
Abox,forexample,isagroupofonlythreevisiblesurfaces.Becauseweknowhowtolightanyofthesurfaceswell,we
canalsolightallofthemwell.Doesthismeanwecanlightanyofthesesurfacesusingonlytheprinciplesdescribedinthe
previouschapter?Usuallynot.Lightingeachvisiblesurfacewellisnotusuallyenough.Wealsohavetothinkabouthow
thosesurfacesrelatetooneanother.Thenwehavetolightandcomposetoadddepth,oratleasttheillusionofdepth,to
thepicture.
Three-dimensionalsubjectsrequiretheirownlightingtechniques.Thelightingtechniquesthatwearegoingto
demonstratearedesignedtoproducethevisualcluesthatourbrainsneedtointerpretdepth.
Interpretingvisualcluesisthekeyconceptonwhichthiswholechapterhangs,sowewillbeginbydescribingwhatsome
ofthesevisualcluesare.Itisdifficulttomakeaphotographwithabsolutelynovisualcluestorepresentdepth.However,it
iseasytodrawsuchapicture.Figure5.1isanexample.Noonecansayforsurewhatthisdrawingisintendedto
represent.Wesaythatitisacube,butyoucouldjustasreasonablyinsistthatitisahexagonwitha“Y”drawninthe
center.
Figure5.1failstosupplyoureyeswiththeessentialvisualcluesthatourbrainsneedtoprocesstheinformationcoming
fromouropticnervesandtodecide,“Thisisathree-dimensionalscene.”
Theonlywaywecanbesurethataviewercanunderstandthatanobjectisacubeistoaddthesevisualclues.Figure5.2
hasexactlythevisualcluesthebrainislookingfor.CompareitwithFigure5.1.
5.1Thisdiagramfailstoprovideanyvisualcluesthatwouldmakeusperceiveitasathree-dimensionalobject.
5.2Herewehaveaddedthosevisualcluesthatthebrainneedstoseedepth.
DEPTHCLUES
Whydoesthesecondpicturelookmorethree-dimensionalthanthefirst?Alookatthedrawingsgivesustwoimmediate
answers.Thefirstisperspectivedistortion:someedgesofthecubeseemtobelongerthanothers,andsomeseemtobe
shorter,eventhoughweknowtheyareallthesamelength.Thecornersallappeartojoinatdifferentangles,eventhough
weknowtheyareall90degrees.
Besidesperspectivedistortion,thereisasecondcluethatourbrainusestoperceivedepth:tonalvariation.Eachfaceofthe
cubeisthesamecolorastheothers,butsomelooklighterandothersappeardarker.
Noticethatthesevisualcluesaresopowerfulthatthebrainperceivesdepththatdoesnotandneverdidexist!Thisisnot
reallyacube;itisonlyabitofinkonpaper.Photographersrecordrealsubjectswithrealdepth,butthatdepthislostinthe
picture.Aphotographonpaperoronamonitorisastwodimensionalasthesedrawings.Photographerswhowantto
maintainasenseofdepthneedtousethesametechniquesthatillustratorsdo.Ourjobisofteneasierthantheirsbecause
naturedoesthejobforusbyprovidingtherightlightingandperspective,butnotalways.
Bothperspectivedistortionandtonalvariationinfluencelightingdecisions.Lightingproduceshighlightsandshadows,so
itseffectontonalvariationisobvious.Therelationshipbetweenlightingandperspectivedistortionislessobvious,butitis
stillimportant.Viewpointdeterminesbothperspectivedistortionandthefamilyofanglesthatcausesdirectreflection.
Changingviewpointtocontrolthatfamilyofanglesalsoaltersperspectivedistortion;changingviewpointtocontrol
perspectivedistortionalsoaltersthefamilyofangles.
PERSPECTIVEDISTORTION
Subjectsappearsmallerwhentheyarefartheraway.Furthermore,ifthesubjectisthreedimensional,thepartofthesubject
thatisfartherawayappearstobesmallerthanthecloserpartofthesamesubject.Similarly,thecloserpartofthesame
subjectappearstobelarger.Wecallthiseffectperspectivedistortion.
Somepsychologistsbelievethatinfantsperceivemoredistantsubjectstobeactuallysmaller.Nooneissureaboutthis
becausebythetimeweareoldenoughtotalkaboutthematter,ourbrainshavelearnedtointerpretperspectivedistortion
asdepth.Wedoknowthatlearningisinvolved,however;peopleraisedinprimitivesocieties,withoutbuildingsthathave
right-anglecorners,arelesslikelytobefooledbytheillusioninFigure5.3.
5.3Thetwoverticallinesarethesamelength,buttomostpeopleonelookslongerthantheother.
DistortionasaCluetoDepth
Oureyesdeceiveuswhenwelookdownrailwaytracks,butourbrainsdonot.Therailsappeartoconvergeinthedistance,
butweknowthattherailsareparallel.Weknowthattheyarethesamedistanceapartamiledownthetrackastheyare
wherewearestanding,sothebrainsays,“Thetracksonlyappeartoconvergebecausetheyaredistant.”Buthowdoesthe
brainknowthatthetracksaredistant?Thebrainanswers,“Theymustbedistantbecausetheyappeartoconverge.”(The
flowofthislogicmustshockcomputerprogrammers,buttheyareaccustomedtothelimitationsofinferiorhardware.)
Weassumethebrainactuallyusesamorecomplexprocess,buttheeffectisthesame:perspectivedistortionisoneofthe
majorvisualcluesthatourbrainsusetoperceivedepth.Controllingthisperspectivedistortionallowsustomanipulatethe
illusionofdepthinthepicture.
Conventionalphotographyistwodimensional.(Fewphotographersshootholograms.)Viewersnoticethelengthandwidth
ofaprintedpicturebutnotthethicknessofitspaper.Weperceivedepthinthephotographdespitethefactthatitdoesnot
reallyexist.Figure5.4provesit.
Theforegroundchesspiecesclearlyappeartobeinfrontofthoseinthebackground.Butthe“foreground”and
“background”existedonlyinthescene,notinthispicture.Thisimageisprintedonaflatpapersurface.Perspective
distortioniscriticaltothissenseofdepththatphotographyconveys.
Oneofthemainreasonsweknowthatthisscenehasdepthisthatthelinesthatdelineatethesquareshapeofthe
chessboard—and,toa
5.4Althoughthisphotographisaflat,two-dimensionalrepresentationofthescene,weperceivedepthinit.
lesserextent,thesquaresonit—lookdistorted.Inreality,thoselinesareparalleltoeachother.That,however,is,asyou
cansee,notthecaseinthepicture.Liketherailroadtrackswediscussedearlier,theselinesconvergeatapointonan
imaginaryhorizon.Thisdistortiongivesthebrainastrongvisualcluethatitisseeinglength,width,anddepth.
ManipulatingDistortion
Withingreatlimits,wecanincreaseanddecreasetheamountofperspectivedistortioninaphotograph.Thismeansthatwe
cancontrolthesenseofdepthourpicturesgivetoviewers.
Controllingthedegreeofperspectivedistortioninapictureissimplicityitself.Thecloserwemovethecameratowardthe
subject,thegreaterthedistortionwillbe.Conversely,thefartherthecameraisfromthesubject,thelessitwillbe
distorted.Itisthateasy.
InFigure5.5,weseetheeffectofthefirsthalfoftherule.Itisthesamechessboard,butthecamerahasbeenmovedmuch
closertoit.(Ofcourse,changingthecameradistancealsochangesthesizeoftheimage,butwecroppedthepicturesto
keepthesamesubjectsizeinallofthem.)
Seethatthecloserviewpointincreasesthedistortion.Thelinesthatdefinethechessboardappeartoconvergemuchmore
radicallythantheydidinthefirstphotograph.
ExactlythereversetakesplaceinFigure5.6.Thistimewemovedthecameraback.Noticehowthereislessdistortionin
thispicture.The
5.5Movingthecameracloserincreasedperspectivedistortionandmadetheparallellinesthatruntowardthehorizonappeartoconverge.Thisisoneofthevisualcluesthatthebrainusestoperceivedepth.
5.6Withthecamerafartheraway,parallellinesappeartoconvergeless.
linesinitconvergefarlessobviouslythantheydoineitherofthetwopreviousillustrations.
TONALVARIATION
Thesecondmajordepthclueistonalvariation.Tonalvariationmeansthattherearelightareasanddarkareasinthe
subject.Ifthesubjectisacube,idealtonalvariationmeansthattheviewerseesahighlighted
Whenmostphotographersfirstuseawide-anglelens,theydecidethatthelensintroducesagreatdealofdistortion.Thisisnotquiteaccurate.
Camerapositiondeterminesperspectivedistortion,notthelens.
Toprovethis,wemadeeverypictureofthechessboardwiththesamewide-anglelens.Thismeansthatwehadtoenlargetheimagemadeatan
intermediatedistancesomewhat,andwehadtogreatlyenlargetheimagemadeatagreaterdistance.Thoseenlargementsproducedimages
whosesizesmatchtheonemadewiththecameracloser.Hadweusedlongerfocallengthlenses,wewouldnothavehadtoenlargethosetwo
images,buttheshapeofthechessboardwouldhavebeenthesameastheshapesinthethreepicturesweshow.
Choosingalensoftheappropriatefocallengthdoesallowustocontrolimagesizetomakeitfitthesensorsize.Assumingwewanttheusable
imagetoexactlyfillthesensor,ashortfocal-lengthlensallowsusaviewpointthatproducesperspectivedistortion.Alongerlensallowsustogetfar
enoughfromthesubjecttominimizeperspectivedistortionwithouthavingtogreatlyenlargetheimagelater.Ineachcase,theviewpointdetermines
thedistortion,notthelens.Extremelywide-anglelensesandinferiorlensesmayproducetheirownothertypesofdistortion,butnotperspective
distortion.
side,ashadowedside,andasidethatispartlyshadowed.(Weuse“side”forconvenience.Oneofthesesidescouldbethe
topofthecube,oreventhebottom,ifthecubeissuspendedaboveus.)Goodlightingdoesnotalwaysrequirethisideal,
buttheidealisstillthestandardweusetoevaluatewhateverlightingexists.
Thesehighlightsandshadowsaredeterminedbythesizeandpositionofthelightused.Wetreatsizeandpositionastwo
differentconcepts,buttheyarenotmutuallyexclusive.Onecangreatlyinfluencetheother.Alargelight,forexample,
illuminatesthesubjectfrommanydifferent“positions”atthesametime.Intherestofthischapter,wewillseehowthese
twovariablesrelate.
THESIZEOFTHELIGHT
Selectingthesizeofthelightisoneofthemostimportantstepsinstudiolighting.Timeofdayandweatherdeterminethe
sizeofthelightoutdoors.
Thepreviouschapterdiscussedhowadjustingthesizeofthelightmakestheedgesoftheshadowsharderorsofter.Iftwo
shadowsrecordasthesamegray,ahardshadowwillbemorevisiblethanasoftone.Forthisreason,ahardshadowoften
increasestheillusionofdepthmorethanasoftone.Whenweunderstandthisconcept,wehaveanotherwaytomanipulate
thetonalvalues,andthuscontrolthesenseofdepth,inourpictures.
Thisseemstosaythathardlightsarebetterlights,butdepthalonedoesnotmakeagoodpicture.Ashadowthatistoohard
canbesovisiblethatitcompeteswiththeprimarysubject.Becausewecannotofferfirmrulesaboutwhatsizelightis
alwaysbest,wewillexplorethegeneralprinciplesinmoredetail.
LargeLightsversusSmallLights
InChapter2wediscussedthefollowingbasicprinciples:asmalllightsourceproduceshard-edgedshadows,andalarge
oneproducessoft-edgedshadows.Mostofourlightsaresmall.Portabilityandcostrequireit.Therefore,photographers
moreoftenneedtoenlargeasmalllightthanthereverse.
Diffusingscreens,umbrellas,andbouncecardsallincreasetheeffectivesizeofanylight.Theeffectofanyoftheseis
aboutthesameasthatofanother.Becauseallofthesedevicescanproduceidenticalpictures,wepicktheonethatismost
convenient.Thus,ifthesubjectissmall,wearemorelikelytouseaframedsheetofdiffusionmaterialbecausewecan
placeitclosetothesubjectforbrighterillumination.It'shardertoconstructaverylargediffuser,sowearemorelikelyto
bouncethelightfromawhiteceilingtolightalargesubject.
Outdoorswecanachievethesameeffectbywaitingforanovercastday.Cloudsmakeexcellentdiffusionmaterial,
effectivelyincreasingthesizeofthesunlightsource.Dependingontheavailabletimeandtheaccessibilityofthesite,
somephotographerswaitforadaywiththerightamountofcloudcover.
Lackingthetimetowaitforthebestday,thesameframeddiffusionmaterialweuseinthestudioisalsogoodforsmall
outdoorsubjects.Alternatively,wecankeepthesubjectintheshade.Thenthelargeopensky,insteadofthesmalldirect
sun,servesastheprimarylightsource.(Although,withoutcompensation,asubjectlitonlybytheopenskycanbequite
blue.)
DistancefromtheSubject
Youmayhavebeensurprisedthatintheprecedingsectionwereferredtothecloudsandtheskyaslargerlightsources
thanthesun.Acorollarytotheeffectofthesizeofthelightrelatestothedistancebetweenalightandthesubjectit
illuminates.Thecloseralightistothesubject,thesoftertheshadowsare;thefartheralightisfromthesubject,theharder
theshadowsbecome.Thesunbehavesasasmalllightsourcetopeopleonearthbecauseitissofaraway.
5.7Whenclosetoasubject,thelightraysfromalargelightsourcestrikethesubjectfrommanyangles.Thecloserthelightis,thesofteritsshadowsare.
Rememberthatlargelightsproducesoftshadowsbecausetheyilluminatethesubjectfrommoredifferentdirections.
Figure5.7showsthis,butlookatwhathappensinFigure5.8whenwemovethesamelightsourcefartheraway.Thelight
stillemitsraysinmanydirections,butonlyanarrowrangeoftheseraysstrikesthesubject.
Movingalightfartherfromthesubjectincreasesitscontrastbyreducingtherangeofanglesfromwhichtherayscan
strikethesubject.Thisisjustanotherwayofsayingthatlargelightsproducesoftshadowsandsmalllightsproducehard
ones.Thecloserwemovealighttoasubject,thelargerthatlightsourcebecomesinrelationtoit.
Photographersusingportablestrobesinsmallroomssometimesinsistthattheoppositeistrue.Theyknowthatmovingthe
lightfartherfromthesubjectsoftenstheshadows,ratherthanmakingthemharder.Thisisbecausemovingthelightfarther
awayreflectsmoreoftheraysfromthesurroundingwalls.Theroomitselfbecomesamoreimportantcomponentofthe
lighting.Theroomislargerthanthestrobe,sotheprincipleisnotcontradicted.
5.8Movingthelightfartherawaycausestheraysstrikingthesubjecttobemoreparallel.Thisproducesharderedgedshadows.
THEDIRECTIONOFTHELIGHT
Thedirectionofthelightrelativetothesubjectdetermineswhatpartofthesubjectishighlightedandwheretheshadows
fall.Lightfromanydirectionmaybegoodinanyparticularcase,butonlyafewofthemaregoodforemphasizing
dimension.
Lightcomingfromthedirectionofthecameraiscalledfrontlightingbecauseprimarilythefrontofthesubjectis
illuminated.Frontlightingshowstheleastpossibledepthbecausethevisiblepartofthesubjectisentirelyhighlighted.The
shadowfallsbehindthesubjectwherethecameracannotseeit.Thecameraseesnotonalvariationand,therefore,no
depth.Forthisreason,frontlightingisoftencalledflatlighting.However,theapparentlackofdepthisnotalwaysa
deficiencyand,infact,cansometimesbeavirtue:front-litportraitscanbeflatteringbyminimizingskintexture.
Backlightingalsofailstorevealthedepthofanobject.Comingfrombehindthesubject,backlightingputsthevisiblepart
ofthesubjectinshadow.Thiscanadddrama,butwithoutotherlights,itwillnotadddimension.
Becausetheperceptionofdepthrequiresbothhighlightandshadow,alightingdirectionbetweenfrontandbacklighting
maximizesthatperception.Suchlightingiscalledsidelighting.Mostgoodlightingis,atleasttosomeextent,side
lighting.
Stilllifephotographersoftenusetoplightingfortabletopsubjects.Toplightingrepresentsdepthtothesameextentasside
lightingbecauseitgivesthesubjectthesameproportionofhighlightandshadow.Webaseourchoicebetweenthem
entirelyontaste.Thisisaquestionofwherewewantthehighlightandshadow,notofhowmuchofeach.
Lightdirectlyfromthesideorthetopoftenconcealstoomuchofthesubjectdetailinshadow.Sophotographersmaypull
thelighttowardthecameratoapositionbetweenthoseofsidelightingandfrontlighting.Thiscompromiseiscalledthree-
quarterlighting.
Youcanjustifiablydecidetouseanyoftheselightingdirectionsforanysubject.Thethinkingprocessyouuseismore
importantthanwhateverrulesweoffer.Yourdecisionwillalmostalwaysbegood,aslongasyouconsiderwhateach
directionaccomplishesandhowwellitfulfillsyourobjectiveforaparticularsubject.
Nowwewilllookatarealsubjectanddecideononegoodwaytolightit.Thesubjectwillbeadriedgourd,andour
objectivewillbetolightittoemphasizedepth.
LightontheSide
Onewayofproducingtheshadowsthatweneedasdepthcluesistopositionthemainlightononesideofthesubject.We
triedthisinFigure5.9,usingasmall,high-contrastlightsothatyoucouldseetheshadoweasily.
Thisisapotentiallygoodapproach,butitisusuallynotthebestonefortabletopsubjects.Thecombinationofhighlight
andshadowdoesshowdimension,butthehardshadow,locatedwhereitis,distractsfromtheprimarysubject.Wecould
improvethisphotographwithalargerlight.Thatwouldsoftentheshadow,makingitlessnoticeable.However,the
positionoftheshadowwouldstillcauseittocompete.(Thegourdisthesubject,nottheshadow.Onanyotherdaywe
mightdecidetheshadowisthesubject,oratleastanimportantsecondarysubject.Thenwewouldlightandcomposethe
picturetocapitalizeonthatshadow.)
5.9Theshadowhelpsthebrainperceivedepth,butinthiscasetheshadowisobtrusive.
Theonlywaytokeepthisparticularshadowfromdrawingtheeyeawayfromthesubjectwouldbetosoftenitsomuch
thatitwouldnotexistatall.Butnoticethattheshadowalsoprovesthatthesubjectissittingonatable.Withoutthe
shadow,thebrainwouldhavenowayofknowingwhetherthesubjectisonthetableorfloatingaboveit.
Therelationshipofthesubjecttothebackgroundtellsthevieweranessentialmessageaboutthedepthinthescene.
Conveyingthatmessagerequireskeepingtheshadow.Becausewemustnotgetridoftheshadow,thenwehavetoputit
somewhereelse.
LightabovetheSubject
Theleastdistractingplacefortheshadowinmostcompositionsisdirectlyunderandinfrontofthesubject.Thismeans
placingthelightaboveandslightlybehindthesubject.Figure5.10wasshotwithsuchanarrangement.Nowtheshadow
givesthesubjecta“ground”onwhichtosit.
Althoughtheplacementoftheshadowisimproved,thepicturestillhastwoproblems.Thefirstisthatthesubjectstilldoes
nothaveasmuchdepthasitneeds.Thetopofthesubjectishighlighted,buteithersideisaboutthesamegrayastheother.
Thelackoftonaldistinctionbetweentheleftandrightsidesdetractsfromtheillusionofdepth.Thesecondproblem,to
manyphotographers,isthattheshadowunderthe
5.10Withasmalllightabovethesubject,theshadowissmallenoughtobelessobtrusiveanditgivesthegourda“ground”onwhichtosit.However,theshadowisstilltoohard.
gourdistoohard.Beingsohardmakesitobtrusive,toomuchofanelementinthepicture.
Wewillfirstdealwiththehardshadow.Weusedasmalllightinthisexampletomakeiteasiertoseewheretheshadow
falls.Nowthatyouhaveseentheshadowclearly,wewillsoftenit.Wewillsubstitutealargesoftboxfortheearliersmall
light.Figure5.11isadiagramofthelighting.Figure5.12istheresult.
Noticeinthelightingdiagramthatthesoftboxisangledslightlytowardthecamera.Thistiltisnotessential,butitis
common.Thetiltkeepstheseamlessbackgroundevenlyilluminated.Noticethatthelightisclosertothetoppartofthe
backgroundandthatkeepingthelightlevelcouldlightthatareatoobrightly.Theotherreasonfortiltingthelightistocast
morelightonanyreflectorcardswemightdecidetouseforfilllight.
FillLight
Sometimesasinglelargeoverheadlightissometimesallweneed,butnotalways.Thislightingfailsifthesubjectistall
andthinorhasveryverticalsides.Thetonalvariationproducedbythesingleoverheadlight
5.11Lightingwithasoftboxmakestheshadowmuchsofterandunobtrusive.
5.12TheresultofthelightingshowninFigure5.11.
maybetooextremeand,comparedwiththetopofthesubject,thefrontandsidearetoodark.Thiscanevenhappenfora
shallow,flatsubject(suchasanaudioamplifier)ifthedetailinitsfrontishighlyimportantandwhat'sontopisnot.
Figure5.12showsabitofthisproblem;it'snotterriblethewayitis,butalittlemorelightonthefrontofthegourdwould
benice.
Themostobvioussolutiontothisproblemistoaddanotherlighttofillinsomeoftheshadow.Thisisnotalwaysthebest
solution,norisitalwaysnecessary.Placingthefilllighttoonesidemaycausecompetingshadows,suchasthoseshownin
Figure5.9.Butplacingthefilllightoverthecameramaylightthesubjecttooevenly.Thatcoststheverydepthweare
tryingtoachieve.
Wecanavoidaddingproblemsbyusingafilllightthatisassoftaspossibleandasdimaspossible,provideditisstill
brightenoughtodoitsjob.Ifthefillissoft,theadditionalshadowwillbetoopoorlydefinedtocompete.Ifthefillisdim,
acompetingshadowwillnotbedarkenoughtobevisible.
Keepingthefillsoftmeansusingalargeenoughsource.Averyroughruleistouseafilllightnearthesubjectthatisabout
halfthesizeofthemainlight.Brighterfilllightsusuallyneedtobelarger,butweakeronescanbesmallerwithout
creatingnoticeableextraneousshadows.
Sometimesasimplereflectorcardprovidesenoughfill.Wecanaddreflectorcardsoneachsideofthesubjectordirectly
underthecamera.Theamountoffilllightaffectsboththebrightnessofthesubjectandtheamountofthegroundshadow
lost.Ourchoiceoffillcardwillvarywithboththesubjectandthebackground.
Figure5.13wasmadewithasilverreflectorcardtotherightofthegourd.Thelightgraybackgroundreflectedenough
lighttoeliminateanyneedforafillcardtotheleftofthesubject.
Awhitebackgroundmighthavereflectedsomuchlightthatwewouldhaveneedednoreflectorcardsatall.Ablack
backgroundwouldhavereflectedsolittlelightthatwewouldhaveneededstrongerfill.
Wecanuseanycombinationofreflectorcardsandadditionallights,dependingonhowmuchfillthespecificsubject
needs.Theleastamountoffillwearelikelytouseisthelightreflectedfromalightbackgroundsurfaceonwhichthe
subjectsits.Inthosecaseswemayalsodecidetoputablackcardononesideofthesubjectsothatbothsidesdonotget
equalfill.(Wewillshowanexampleofthiswiththewhite-on-whitesubjectinChapter9.)Themostfillwearelikelyto
needisalightbehindalargesheetofdiffusionmaterialononesideofthesubject,plusasmallersilvercardorawhiteone
ontheotherside.
5.13Afillcardlightensthefrontofthegourdbyreflectingsomeofthelightfromtheoverheadsoftbox.
Thephysicalarrangementoftheapparatususedinthephotographinfluenceshowmuchfreedomwehaveinpositioning
thereflectorcard.Sometimeswecanputthecardwhereverweplease,butonotheroccasionsthereisonlyonepossible
positionthatiscloseenoughtothesubjectbutstilloutoftheimagearea.Thismayrequireusingawhitecardwhenwe
mightotherwisepreferasilverone.
Asilvercardusuallyreflectsmorelightontothesubjectthanawhiteone,butnotalways.Rememberthatasilvercard
producesdirectreflections.Forthisreason,thesilvercardhasitsownlimitedfamilyofanglesfromwhichreflectioncan
occur.Inacrowdedarrangement,theonlypossiblepositionofasilvercardmaybeatananglefromwhichitcanreflect
nolighttothesubject.Incontrast,mostreflectionfromawhitecardisdiffuse.Becausetheangleofawhitecardisless
critical,fromsomepositionsitwillreflectmorelighttothesubjectthanasilverone.
Noticethatthesizeofthemainlightalsoinfluencesourchoiceofreflectorcards.Abright,smoothsilvercardproducesa
mirrorimageofthemainlight.Therefore,ifthemainlightislarge,thenalargesilvercardwillserveasasoftfilllight.A
smallsilvercardwillbehaveasahardfillforthesamereasonanyothersmallsourceishard.Ifthemainlightissmall,
however,asilvercardreflectingthatlightwillalwaysbeahardfill,regardlessofitssize.Awhitereflectorcardistheonly
reflectorthatcanprovidesoftfilllightfromasmallmainlight.
Finally,eventhoughthebackgroundsurfaceoftenprovidesadequatereflectedfill,bewareofcoloredbackgrounds,
especiallyifthesubjectitselfiswhiteorpastel.Fillreflectedfromacoloredbackgroundcancolorthesubject.Sometimes
wehavetoaddmorefillfromawhitelightsourcetoovercomethecolorcastcausedbythebackgroundsurface.Wemay
alsoneedtocoverpartofthebackgroundsurfacewithblackcardstogetridofoff-colorreflectedfill.
AddingDepthtotheBackground
InFigure5.11weusedacurvedpaperbackgroundcalledasweep.Hunginthismanner,thebackgroundcoversthetable
onwhichthesubjectsitsandalsoconcealswhatevermightbebehindthetable.Thecameraseesnohorizon,noristhe
gentlecurveofthepapervisibleaslongaswedonotlettheshadowofthesubjectfallonthatpartofthebackground.The
brainthinkstheentiresurfaceishorizontalandextendsapossiblyinfinitedistancebehindthesubject.
Sofar,wehaveusedsimple,single-tonebackgroundsforthesakeofsimplicityinourexamples.Notonlycanthisproduce
boringpictures,butsuchlightingalsofailstocapitalizeontheillusionofinfinitedepthinthebackground.Wecangreatly
enhancethisillusionbyilluminatingthebackgroundunevenly.
Wecallthisunevenilluminationfalloff.Asweareusingtheterm,itmeansatransitioninthescenefromlighttodark.
Falloffcanoccurinanyareaofthepicture.Photographersmorecommonlyusefalloffatthetopofthepicture;itlooks
goodthereandhappenstobetheeasiestplacetoputitwithoutinterferingwiththelightingoftheprimarysubject.
LookatFigure5.14.Noticehowthebackgroundtonefallsofffromlightgreenintheforegroundtoblackinthe
background.
Thedifferenceinthetonalvalueoftheforegroundandbackgroundtonesprovidesanothervisualcluetosuggestdepth.
Figure5.15showshowweproducedthefalloff.Allwehadtodowasaimthelightmoretowardthecamera.
Thissimplechangeinoursetallowedlessofittofallontheseamlesspaperatthebackoftheset.
Noticethatweaddedagobooverthelens.Itwasimportantbecausethemoreweaimedthelighttowardthecamera,the
greaterwasthepossibilitythatwewouldproduceseriouscameraflare.
5.14Theunevenilluminationofthebackground,calledfalloff,addsdepthtoapictureandhelpsseparatethesubjectfromthebackground.
5.15Aimingthelighttowardthecameraproducedthebackgroundfalloff.
Thegoboisoftenessentialtopreventflare.
Flare,alsocallednonimaginglight,isthescatteringoflightsothatitgoeswherewedon’twantit.Itexistsineverypicture,usuallytoan
unnoticeableandharmlessdegree.However,thelightinginFigure5.15islikelytoproduceenoughflaretodegradethepicture.Sometimesflare
lookslikeauniformgrayfogovertheentireimage;othertimesitappearsastheunevenstreaksweshowlaterinFigure7.17.
Therearetwodifferentkindsofflare:lensflareandcameraflare.Theeffectofthesetwocanlookthesame.Thedifferencebetweenthemiswhere
thelightgetsscattered.Lensflare,thankstomodernoptics,israrelyaproblemifthelensiskeptclean.Cameraflare,ontheotherhand,isrelatively
unimprovedbyopticaladvances,anditremainsaseriousproblem.
Figure5.16showswhatcausescameraflare.Lightfromjustoutsidethefieldofviewentersthelensandreflectsfrominsidethecameratothe
sensor,degradingtheimage.Allcamerashaveblackinteriorsandallprofessionalcamerashaveridgesinsidetoabsorbasmuchofthis
extraneouslightaspossible,butnocameradesigneliminatesitentirely.
Thewholepurposeofalenshoodistoblocklightcomingfromoutsidethescenebeforeitentersthelens.Lenshoods,unfortunately,sometimesdo
notextendfarenoughforwardtobeofanyhelpinpreventingcameraflare.Thisisparticularlytrueofviewcamerasbecausealenshooddeep
enoughtobeeffectivecanblockpartofthescenewhenthelensistiltedorshifted.Thesolutionistouseopaquecardsasgobos,asinFigures
5.15and5.16.
5.16Cameraflareiscausedbylightfromoutsidethefieldofviewpassingthroughthelensandreflectingfromtheinsideofthecamera.Blockingthelightbeforeitreachesthelensistheonlywaytopreventit.
(Continued)
103
Ifthelightsourceishard,wecanpositionthegobosothatitsshadowjustbarelycoversthelens.However,placingthegoboismoredifficultifthe
lightsourceissoft.Theshadowofthegobomaybesosoftthatwecannottellwhenitadequatelyblocksthelightfallingonthelens.
Becausewenormallycomposeandfocuswiththelensopenedtoitsmaximumaperture,thereislittledepthoffieldintheimageweseeinthe
camera.Thislackofdepthoffieldmaymaketheimageofthegobosounsharpthatitisimpossibletoseeitevenwhenitisintrudingintothepicture
area.Itcanbedifficulttoplacethecardcloseenoughtothefieldofviewtobeusefulwithoutblockingpartofthescene.
Remember,however,thattheglasslensreflectslikeamirror.Withthecameraonatripod,youcanlookintothefrontofthelensandseethe
reflectionofanylightsourcelikelytocauseflare.Movethegoboinfrontofthelensjustfarenoughthatyoucannolongerseethelightsource
reflectedinthelens.Thenpullthegobobackslightlyforsafety.Agobointhatpositioneliminatesalmostallflarewithoutextendingintotheimage.
HOWMUCHTONALVARIATIONISIDEAL?
Wehavesaidthataboxwiththreevisiblesidesneedstohaveahighlightside,ashadowside,andasidewhosetoneis
betweenthosetwo.Nowherehavewesaidhowbrightthehighlightmustbeorhowdarktheshadowshouldbe.Infact,we
neverspecifylightingratiosinthisbookbecausethedecisionhastobebasedonthespecificsubjectaswellaspersonal
taste.
Ifthesubjectisasimplecubewithnoimportantdetailonanyofitssides,wecanmaketheshadowblackandthehighlight
white.However,ifthesubjectisthepackageforaproductwewanttosell,theremaybeimportantdetailonallsides.This
requireskeepingthehighlightonlyslightlybrighter,andtheshadowonlyslightlydarker,thanthethirdside.
Let'slookattwomoreexamples,anofficebuildingandacylinder,onecaseinwhichphotographersareverylikelyto
wantlesstonalvariation,andanotherinwhichwetendtoprefermorevariation.
PhotographingBuildings:DecreasingTonalVariation
ThesametechniquesapplytophotographingthebuildinginFigure5.17astomakingapictureofabrick.Bothcasesneed
thosevisualcluesthataddtheillusionofdepth.
However,specialconsiderationsapplytothebuilding.Thefirstisthatwearelikelytopreferasmallerlightsourceforthe
architecturethanforthebrick.Thisdoesnotsuggestthatarchitecturedoesnotphotographbeautifullyonanovercastday.
Theoppositeistrue.Architecturalphotographyalmostalwaysincludesthesky,however,and
cleanblueskiesareusuallymorepleasingthandingygrayones.Furthermore,ablueskyprobablyhasahard,undiffused
suninit.
Choosingadaywithharderlighthasfurtherimplicationsaboutwherewe“position”thatlight.Thehardershadowismore
visibleand,hence,morelikelytocompetewithotherdetail.Theundiffusedsunlightalsocausesbrighterhighlightsand
darkershadows.Unfortunately,suchhighlightandshadowaremorelikelytoobscuredetails.
Becauseoftheneedtominimizeshadowstoincreasethelegibilityofthearchitecturaldetail,manyphotographerspreferto
takepicturesthatarelitmuchlikethatshowninFigure5.17.Theyliketoworkwith
5.17Thisbuildingisthesamebasicshapeastheotherboxesshowninthischapter.Thesunwasinapositiontoproducerelativelyevenillumination.(Copyright2007byDanCunningham.)
thesunbehindthem,slightlytothesidethatthebuildingfaces,andlowinthesky.Notonlydoessuchlightingproducea
lessdistractingshadow,butbecauseitoccursjustaftersunriseorjustbeforesunset,thesunlightoftenwarmsthecolor
pleasingly.
Weknowthatlesstonalvariationproduceslesssenseofdepth.Butrememberalsothatmoreperspectivedistortion
increasesthedepthillusion.Soasweoptformoreevenillumination,wearealsolikelytolocatethecameraclosertothe
subject.(Architecturalphotographersuseshorter-focal-lengthlensestomakethispossible.)Theconsequentincreasein
perspectivedistortionregainssomeofthelostdepth.
PhotographingCylinders:IncreasingTonalVariation
Nowwearegoingtolookatcylindersandthespecialproblemstheycanpresent.Figure5.18isbasicallyacylindrical
object,butthetonalvariationdoesnotrevealtheshapeverywell.Becausethelightingissoevenacrosstheentiresurface
ofthewoodenbowlingpin,itisdifficulttotellwhethertheobjectisthreedimensional.Thephotographdoesnotcontain
enoughvisualcluesforourbrainstomakeaninformeddecision.
Theproblemiscausedbythefactthatthe“sides”ofthecylinderarenotseparatedbyanyclearlydefinededge.The
shadowblendssograduallyintothehighlightthatsomeofthedimensionaldistinctionislost.Thesolutiontothisproblem
istobuildmoretonalvariationintothescene.Cylindersusuallyneedabrighterhighlightsideoradarkershadowside
thanboxesdo.Figure5.19showswhathappenswhenwemodifythelightingtoachievethis.
Therearetwogoodwaystoobtainthisincreasedtonaldistinction.Oneistokeepthebasiclightingsimilartothatinthe
gourdexamplesbuttouseabrighterreflectorononeside.Thenweusenoreflectoror,ifnecessary,ablackcardonthe
otherside.
WecouldalsoproduceFigure5.19byputtingourmainlightbesideinsteadofabovethesubject.Bylightingonesideof
thecylindermorethantheother,enoughvariationfromhighlighttoshadowsuppliestheillusionofdepth.
Unfortunately,placingthelighttoonesideofthesubjectcreatesapotentialproblem.Theshadowofthesubjectfallson
thetablesurfacebesideit.Aswesawearlier,theshadowisleastlikelytobecomeastrongcompositionalelementifitfalls
atthebottomofthepicture,underthesubject.
Ifwedoplaceourmainlighttothesideofacylindricalsubject,weusuallyuseanevenlargerlightsource.Thisfurther
softenstheshadowandmakesitlesslikelytocompeteforattention.
5.18Thissubjectisbasicallycylindrical,buttheflatlightingdoesnotgiveenoughvisualcluestoshowit.
5.19Lightingthepinfromthesidegivespronouncedtonalvariation—justthecluethatthebrainneedstoperceivedepth.
RememberSurfaceDetail
Finally,rememberthatsurfacedetail,subtlevariationsinbothcolorandtexture,aremostvisibleinthemid-ranges.Look
againatFigure5.19,thebowlingpin,withthisinmind.The“B”logoislargeandgraphicenoughtoholdupunderalmost
anylighting,butifwewanttogetpickyaboutit,wehavetoadmitthatthecenterofthatlogoisrenderedbetterthanits
leftandrightedges.Thelogoissomewhatlessvisiblewhereitsblackedgemeetstheshadowandwheretheglossofits
highlightturnstheblacktoacolorsimilartothatofthewood.Furthermore,ifwewerethemanufacturersofthepin,
insteadofphotographerswantingagoodpicture,wewouldprobablyobjecttothenear-lossofthe“g”inthe“score-king”
partofthelabel.
Somedigitalcamerascompoundthislossbyabruptlyclippingthedetailatabsoluteblackandabsolutewhite.
Photographerswhoshotfilm,especiallynegativefilm,usuallyhadsomeadditionaldetailinboththehighlightandthe
shadowthatcouldbeenhancedinthedarkroom.
Soknowingthattonalvariationisagoodthing,westilldon'tusuallymaximizeit.Wejudgeeachsubjectindividually,
consideringwhatelseisimportantaboutthatsubject,whoisgoingtousethepicture,andhowtheyintendtouseit.
THEGLOSSYBOX
InChapter4wesawthatgoodlightingrequiresdistinguishingbetweendiffuseanddirectreflectionandmakingan
informeddecisionaboutwhichwearegoingtouse.Everythingwesaidaboutlightingasimple,flatsurfaceapplies
equallytothegroupofsurfacesthatmakesathree-dimensionalobject.
Inthischapterwehavediscussedperspectivedistortion,lightdirection,andlightsize.Thesealldeterminewhetherthe
cameracanseealightsourcewithinthefamilyofanglesthatproducesdirectreflection.Nowwearegoingtotalkabout
someofthespecialtechniquesthatarehelpfulwhenphotographingaglossybox.
LookatFigure5.20,adiagramshowingaglossyboxwithtwofamiliesofangles,onethatproducesdirectreflectionfrom
thetopoftheboxandoneforthefront.(Mostcameraviewpointsrequirephotographerstodealwiththreefamiliesof
angles,butitiseasiertoseetheminadiagramshowingonlythetopandfront.)
Ourfirstlightingdecisioniswhethertoproducedirectreflectionortoavoidit:whethertoplacethelightwithinoroutside
thefamilyofangles.
Figure5.21showsaboxwithaveryglossyfinish.Becauseitissoshiny,muchofthedetailofthewoodinitstopis
obscuredbydirectreflection.
5.20Herearetwoofthefamiliesofangleswithwhichwemustcontendwhenshootingabox.Alightsourceineitherofthemwillproducedirectreflection.
FamilyofAnglesforTopofBox
FamilyofAnglesforFrontofBox
5.21Detailsonthetopofthisboxarelargelyobscuredbydirectreflection.Wecouldremedythisbykeepinglightsourcesoutofthefamilyofanglesproducingthatreflection.
Weshouldbeabletoremedythelossofdetailbykeepinglightsourcesoutofthefamilyofanglesthatproducessuch
reflection.Thefollowingisaseriesofstepsthatcanaccomplishthisgoal.
UseaDarkBackground
First,useadarkbackgroundifpossible.AsyoucanseefromFigure5.20,oneofthewaysinwhichglare-producinglight
getstothesubjectisbyreflectingfromthebackground.Lightfromthetabletopcancausedirectreflectiononthesidesof
thebox.Ifweareusingasweep,lightfromitsupperpartcanreflectontheboxtop.Thedarkerthatbackgroundis,the
lesslightreflectsfromit.Thisstepalonemaybeadequateforsomesubjects.
Sometimesyoumaynotwantadarkbackground.Onotheroccasions,youwillfindthatlightthatproducesdirect
reflectioncomesfromsomeplaceotherthanthebackground.Ineithercase,thenextstepisthesame:findthelightcreating
thedirectreflectionandgetridofit.
Intheexamplesthatfollow,wedealwiththefamilyofanglesdefinedbythetopoftheboxwithonesetoftechniques.We
thenuseanother,slightlydifferentprocedureforthefamiliesofanglesassociatedwiththesides.
EliminateDirectReflectionfromtheBoxTop
Therearethreeeffectivewaysofeliminatingdirectreflectionfromtheboxtop.Wecanuseone,orwecanusea
combinationofthem,accordingtotheotherrequirementsofthepicture.
MovetheLightSourcetowardtheCamera
Ifthecameraishigh,thenanoverheadlightcanreflectinthetopofthebox.Thisisparticularlytrueofabanklight.Such
alightissolargethatatleastapartofitisverylikelytobewithinthefamilyofangles.Thiscausesdirectreflectiontobe
brighterandworsethanifalightbackgroundreflectsinthetopofthebox.
Oneremedyistomovethebanklighttowardthecamera.Doingso,asshowninFigure5.22,clearlyrevealsthedetailon
theboxtop.
RaiseorLowertheCamera
Movingthecameraalsochangesthefamilyofangles.Ifanoverheadlightsourcereflectsintheboxtop,loweringthe
cameramovesthefamilyofanglessothatthelightisnolongerinit.Ifthetopofasweepisreflectinginthetopofthe
box,raisingthecameracausesthestudio
5.22Herearesomeofthedifferentwaystoeliminatedirectreflectionsfromtheboxtop.Youcanuseanyoneoracombinationofthem.
areaaboveandbehindthebackgroundtoreflectinstead(Figure5.23).
Fortunately,itisusuallyasimplemattertokeepthatpartofthestudiodark.
UseFalloff
Ifitisnotpossibletouseadarkbackground,wemayatleastbeabletodarkenthatpartofthebackgroundthatcauses
directreflectiononthetopofthebox.Falloffaccomplishesthis.Keepasmuchlightasyoucanfromthebackground.The
lesslighthittingtheboxsurface,thelessthat
willreflectfromit.111
EliminateDirectReflectionfromtheBoxSides
Itisrelativelysimpletogetridofmostofthedirectreflectionfromthetopofaglossybox.Thingsgetmoredifficultwhen
westarttryingtoeliminateitfromthesides.InFigure5.24wehaveturnedtheboxtoponedgetoshowanexaggerated
exampleoftheproblemthatcanoccuronthesidesofthebox.
5.23Hereweseetheresultsofmovingthebanklightforward.Thedetailontheboxtopisnowclearlyvisible.
5.24Forthispicture,weturnedthebox’stoponedgetogiveanexaggeratedexampleoftheproblemsthatcanoccuronthebox’ssides.
PutaBlackCardontheTabletop
Thiswilldarkenpartofthesurfaceandeliminatedirectreflectionfrompartofthesubject.Figure5.25showstheresult.
Thisisaparticularlyusefultechniquewhenwewanttoeliminatesomedirectreflectionsbutnotothers.Forexample,
directreflectioncanobscuretheplasticdialonastereoreceiverwhileatthesametimemakingthealuminumfaceplate
lookbrightandclean.Insuchcases,cuttingtheblackcardtofitjustthefamilyofanglesthatproducesdirectreflectionon
theplasticcansolveoneproblemwithoutcreatinganother.
IfyoulookagainatFigure5.20,youwillseethatiftheboxsideisperfectlyvertical,theblackcardcannotfillallofthe
familyofanglesunlessitiscloseenoughtotouchthebottomofthesubject.Nevertheless,gettingthecardascloseas
possiblewithoutintrudingintotheimageareaisoftenagoodstartbeforegoingontothenexttechnique.
TiptheBox
Sometimesyoucanremoveagoodbitoftheoffendingglarebytippingupthefrontofthebox.Thesuitabilityofthis
tacticdependsontheshapeofthesubject.
5.25Usingadarkcardtotherightoftheboxgetsridofunwanteddirectreflectionsonitssideandrestoresdetail.
Forexample,subjectslikecomputersandkitchenappliancesoftensitontheirownsmallfeetasmallheightabovethe
tabletop.Hidingasmallsupportintheshadowundersuchasubjectissimple.Oncethecameraistiltedtomakethe
subjectappearlevel,thetrickeryisundetectable.
Iftheboxissupposedtobeflushonthetabletop,itiseasierforthecameratoseethattheboxisnotlevel.Wemaybeable
totilttheboxless,ornotatall.Evenaslighttiltcanbehelpful,however,especiallyalongwiththefollowingtechnique.
UseaLongerLens
Therearetimeswhenalongerlenscancometotherescue.Figure5.26showshowalongerlensallowsustoplacethe
camerafartherfromthesubject.Aswesee,thefamilyofanglesissmallerthanitwasinFigure5.20.Thismeanslessof
thetabletopreflectsinthesubject.
FinishwithOtherResources
Ifsomedirectreflectionisstillobscuringdetail,thefollowingtechniquescaneliminateitcompletely.
TryaPolarizer
Ifthedirectreflectionispolarized,alenspolarizingfilterwillgetridofit.Wesuggestedthisasoneofthefirstremedies
totryforthecompetingsurfacespresentedinthepreviouschapter.
If,however,thesubjectisaglossybox,wemoreoftensavethepolarizerasanext-to-lastresort.Theglossyboxusually
haspolarizedreflectiononmorethanoneside.Unfortunately,thereflectionfromonesideislikelytobepolarizedina
directionperpendiculartothepolarizationoftheotherside.Thismeansthatasthepolarizingfiltereliminatesone
polarizedreflection,iteffectivelyincreasesanother.
Therefore,wefirsttrytheprecedingsteps.Then,whateverdirectreflectionisleftisthatwhichisthemostdifficultthing
toeliminate.Thenweusethepolarizertoreducethatreflection.Iftheotherremedieshavebeensuccessful,theslightly
increaseddirectreflectionontheothersideswillnotbeanytrouble.
UseDullingSpray
Yes,therearetimeswhenthedragonwins!TherearetimeswhenMotherNature,physics,andviewpointproduce
reflectionsthatcannot
5.26Usingalonglenssometimeshelpsgetridofunwantedreflections.ComparingthemoredistantviewpointinthisdiagramwiththatinFigure5.20showsthatthefartherwemovethecamera,thesmallerthefamilyofanglesgets.
beeliminatedwithanyofthetechniqueswehavedescribed.Thenweusedullingspray.Itmaymakeanotherwise
unacceptablepicturework.
Beaware,however,thatdullingspraycanreducethesharpnessoftheverydetailyouaretryingtopreserve.Ifthatdetail
happenstobefinetypeorthelike,thelossofsharpnessmaybemoredamagingthanalossofcontrastcausedbydirect
reflection.
Inaddition,thereisalwaysthechancethatthechemistryofthedullingspraywillnotgetalongwellwiththatofthe
subjectuponwhichyouaresprayingit.Sobecareful.Alwaystestalittlebitofsprayonasmall,andhopefully
insignificant,partofyoursubject.Nottotakethisprecautionistocourtdisaster!
UseDirectReflection
Wechosetheglossyboxexampletobeoneinwhichdirectreflectionisobviouslyoffensive.Butifdirectreflectiondoes
notobscuredetail,weareusuallymorelikelytotrytomaximizeitratherthantoavoidit.Afterall,ifdirectreflectionis
essentialtothesurface,capitalizingonthatreflectionproducesanimageofthesubjectthatlooksasmuchlikethereal
thingaspossible.Wewilldiscussthespecifictechniqueinthenextchapter.
6
Metal
Manystudentandapprenticephotographersthinkmetalisoneofthemostdifficultphotographicsubjectsandconsider
assignmentsthatrequirethemtophotographmetaltobenothinglessthancruelandunusualpunishment.However,when
theymastertheassignment,theydiscoverthatnothingcouldbefurtherfromthetruth.Metalisnotdifficult,and
photographyteachershaveslightlylessthansadisticmotiveswhentheyrequiresuchwork.
Thereareaboutahalfdozenclassicsubjectsthatallphotographersaresupposedtoencounterastheylearnlighting.These
subjectsteachbasictechniquesthatenableustolightanything.Metalisoneoftheclassicsubjectsforgoodreason.
Brightlypolishedmetalproducesalmostnothingbutunpolarizeddirectreflection.Thisconstancymakesmetalarealjoy
tophotograph.Itispredictable.Itplaysbytherules.Wecantellbeforewebegintolightthescenewhatsizethelight
needstobe.
Moreover,whenitdoesturnouttobeimpossibletopositionthelightsourcewhereitneedstobetolightthepicturewell,
wecanalsoseetheproblemearlyintheprocess.Weseldominvestalotoftime,onlytofindthatwhatweareattempting
cannotbedoneandthatwehavetostartthelightingarrangementoverfromthebeginning.
Inaddition,becausethedirectreflectioninmetalislargelyuncontaminatedbyothertypesofreflections,itiseasytosee
howthisreflectionbehaves.Therefore,learningtophotographpolishedmetalhelpsgiveonethecapabilitytoseeandto
managedirectreflectionwheneverandwhereveritoccurs,evenwhenotherkindsofreflectionscompeteinthesame
scene.
Wewillintroducenewconceptsandtechniquesinthischapter.Themostimportantsubjectmatteristhesimplest:flat,
brightlypolishedmetal.Aflatpieceofmetal,withoutanyotherobjectsinthescene,iseasytolight,evenwithoutmuch
thoughtorunderstandingofthe
relevantprinciples.Butsuchsimplesubjectmattercandemonstratethemostsophisticatedtechniques—techniquesthat
caneventuallymakeeventhemostdifficultassignmentspossible.
Muchofwhatfollowsisbasedonthefamilyofanglesthatcausesdirectreflection.WeintroducedthisfamilyinChapter
3.Wehaveusedtheconceptineachsucceedingchapter,butinnoneofthemwasitasvitalasitbecomeswhendealing
withmetal.
FLATMETAL
Brightlypolishedmetalactslikeamirror:itreflectswhateverisaroundit.Thismirror-likequalitymeansthatwhenwe
photographmetal,wedonotmakeapictureofjustthemetalitself.Wealsomakeapictureofitssurrounding,or
environment,asitisreflectedinthemetal.Thatmeansthatwemustprepareasuitableenvironmentbeforewephotograph
themetal.
Weknowthatdirectreflectioncanbeproducedonlybyalightsourcethatiswithinalimitedfamilyofangles,relativeto
thesubjectandtothecamera.Becausethemetalreflectsitsenvironment,itmakessensethatthesmallerthatfamilyof
anglesis,thelessoftheenvironmentwehavetoworryabout.Asmallpieceofflatmetalhasonlyasmallfamilyofangles
fromwhichdirectreflectioncanbeproduced.Thismakessuchapieceofmetalthesimplestexamplewecanusetotalk
aboutthegeneralprinciplesoflightinganymetal.
Figure6.1isadiagramofapieceofflatmetalandacamera.Notethatthecamerapositionisessentialinanylighting
diagraminvolvingmetal.Thisisbecausethefamilyofanglesdependsonthepositionofthecamerarelativetothesubject.
Therefore,therelationshipbetweenthecameraandthesubjectisatleastasimportantasthesubjectitself.Weknowthat
directreflectioncanbeproducedonlybyalightlocatedwithinthelimitedfamilyofanglesweshowhere.
BrightorDark?
Oneofthefirstdecisionsthatwehavetomakewhenwephotographapieceofmetalishowbrightwewantittobe.Do
wewantittobebright,dark,orsomethinginbetween?Theanswertothisquestiondeterminesthelighting.
Ifwewantthemetaltoappearbrightinthephotograph,wemakesureourlightsourcefillsthatfamilyofanglesthat
producesdirectreflectiononthemetal.If,however,wewantthemetaltobedarkinthepicture,weputthelightanywhere
else.Eitherway,thefirststepinlightingmetalistofindthatfamilyofangles.Afterthat,thetaskisstraightforward.
SubjectSizeandShapeDeterminesFamilyofAngles
CameraPositionDeterminesFamilyofAngles
6.1Thefamilyofanglesthatproducesdirectreflectiondependsonthepositionofthecamerarelativetothesubject.
FindingtheFamilyofAngles
Practicemakesiteasytoanticipatewherethefamilyofangleswillbe.Experiencedphotographersusuallygetthelightso
closetotheidealpositiononthefirsttrythatonlyminoradjustmentneedstobemadeafterthefirstlookinthecamera.
However,ifyouhaveneverbeforetriedlightingmetal,itmaybedifficulttovisualizewherethefamilyofanglesexistsin
space.
Wearegoingtoshowyouatechniquethatalwaysfindsexactlywherethefamilyofanglesis.Youmaydecidetouseit
oftenoryoumaydecidetouseitonlyformoredifficultsetups,dependingonyourneed.Eitherway,anabbreviated
versionofthisroutineisadequateformostphotographs.Ifthisisthefirsttimeyouhavetriedtolightmetalexpertly,itis
probablyworthtryingtheentirefollowingsequenceofstepsatleastonceasanexercise.
PositionaWhiteTargetWhereYouThinktheFamilyofAnglesWillBe
Thiswhitetargetcanbeanyconvenientlargesurface.Theeasiestwillbewhateverlargepieceofdiffusionmaterialyou
mighteventuallyuse
6.2Thepossiblepositionsforthetestsurfaceinthisexercisearealsowherewemightsuspenddiffusionmaterialifwewishedtolightthemetalbrightly.
tolightthemetal.Figure6.2showstwopossiblepositionswherewemightsuspendalargediffusionsheetoverthemetal.
Youdonotknowexactlywherethefamilyofanglesisatthispoint.Usealargerwhitesurfacethanyouthinkyouneedto
fillthoseangles.Thelesssureyouareofwheretheanglesare,thebiggerthesurfaceneedstobe.
PlaceaTestLightattheCameraLens
Wecallthisa“test”lighttodistinguishitfromwhateverlightweeventuallyusetomakethepicture.Thetestlightneeds
tohaveanarrowenoughbeamtolightthemetalwithoutilluminatingthesurroundingarea.Asmallspotlightisideal,buta
flashlightisadequateifyoucankeeptheroomdark.
Ifyouarephotographingasmallpieceofmetalfromacloseworkingdistance,thetestlightmustbeexactlyatthelens
position.Thismayrequiretemporarilyremovingthecamerafromthetripod.Alternatively,ifthecameraisaviewcamera,
youmaybeabletotemporarilyremoveboththelensandthecamerabackandaimthetestlightthroughthe
6.3Atestlightinplaceofthecamerareflectsfromthemetaltoshowwherethefamilyofanglesislocated.Newsflash:Sincethelastprintingofthisbook,acleverreaderhassuggestedusingalaserpointerasthetestlight.Shouldworkwell!
camera.Becarefulofthistactic!Aphotographiclighttooclosetoablackcameracanquicklyheatupthecameraenoughtocauseveryexpensivedamage.
Whenthecamerahasalonglensandthedistancetothesubjectisgreat,itisusuallynotnecessarytoplacethetestlightatexactlythelensposition.Positioningthelightasclosetothelensaspossibleapproximatestheidealwellenoughformorepracticalpurposes.
AimtheTestLight
Aimthetestlightatthepointonthemetalsurfacethatisnearesttothecamera.Thelightwillreflectoffthemetalandontothetestsurface.AsweseeinFigure6.3,thepointatwhichthebeamstrikesthetestsurfacemarksthenearlimitofthefamilyofangles.Useremovabletapetomarkthespot.
Ifthebeamoflightisbroadenoughtocovertheentiremetalsurface,youcanleaveitinpositionwithoutmovingitfortherestofthis
exercise.If,however,thetestlightilluminatesonlypartofthesurface,aimitnowatthefarthestpointonthemetal.Thelightreflectedfromthatpointonthemetalwillstrikethetestsurfaceatthefarlimitofthefamilyofangles.Onceagain,markthetestsurfacewithtape.
Similarly,markasmanypointsasyouneedtoseewherethefamilyofangleslies.Theshapeofthemetalsubjectdeterminesthenecessarynumberofpoints.Attheleast,youwillprobablydecidetomarkthenearandfarlimitsofthefamilyofangles.Ifthemetalisrectangular,youmaydecidetomarkthepointsatwhichthecornersreflectlightontothetestsurface,insteadoftheedges.
StudythePositionandShapeoftheAreaMarkedontheTestSurface
Youwillalmostneverneedalightsourceoragobothatexactlyfitsthefamilyofangles.Nevertheless,thisisgoodpractice,sousethisopportunitytoexamineexactlywherethoseanglesare.Alittleextratimeinvestednowwillpaybackdividendslater.Preciselylocatingthefamilyofanglesnowwillallowyoutoguessitspositionmorequicklyinafutureprojectwithoutgoingthroughthiswholemeasurementprocedureagain.
Noteespeciallythatthepointreflectinginthemetaledgeatthebottomoftheimagecorrespondstothelimitmarkedatthetopofthetestsurfaceandviceversa.Rememberingthiswillmakeiteasytofindthesourceofglareorhotspotsonanytypeofsubjectfromnowon.
Therelationshipsyouproveinthisexerciseapplytoothercameraandsubjectorientations.Thediagramhererepresentsasideviewofacameraphotographingasmallpieceofmetalonatable.Ofcourse,itcouldjustaseasilybeabird’s-eyeviewofacameraphotographingabuildingwithamirroredglassfront.Thentheareamarkedonthetestsurfacemightcorrespondtotheportionoftheskyreflectedinsuchabuilding.
LightingtheMetal
Usingtheforegoingtest,experiencedjudgment,oracombinationofthetwo,wefindthefamilyofanglesfromwhichalightcanproducedirectreflectioninthemetal.Next,wehavetodecidewhetherwewantthemetaltobebrightordarkinthepicture.Thisisacriticalstepbecauseitleadstotwoexactlyoppositelightingsetups.
Insomephotographs,themetalneedstobeabsolutelywhitewhiletherestofthesceneisasdarkaspossible.Onotheroccasions,wedecidetokeepthemetalblackinanotherwisehigh-keyscene.Moreoftenweliketoseesomethingbetweentheseextremes,butlearningtoproducetheextremesmakesthecompromiseeasiertoobtain.
KeepingtheMetalBright
Becausephotographersusuallychoosetomakethemetalintheirpictureslookbright,wewilldealwiththatcasefirst.Ifweassumethatwewanttheentiresurfaceofthemetaltophotographbrightly,we
thenneedalightsourcethatatleastfillsthefamilyofanglesthatproducesdirectreflection.Notethatbecausepolishedmetalproducesalmostnodiffusereflection,lightcomingfromanyotheranglewillhavepracticallynoeffectonthemetal,regardlessofhowbrightitisorhowlongtheexposure.
Itisalsoimportanttorealizethatalightthatjustfillsthefamilyofanglesistheminimumlightsizewecanuse.Later,wewillshowyouwhyweroutinelyusealightlargerthantheminimum.Fornow,wewillassumethattheminimumsizeisadequate.
Figure6.4showsonepossiblelightingarrangement.Wehaveusedalightonaboomaboveadiffusionsheetandhaveadjustedthedistancefromthelightheadtothediffusionmaterialsothatthebeamapproximatelyfillsthefamilyofanglesthatwemarkedearlier.
Wecoulduseanopaquewhitereflectorcardinsteadofthediffusionsheet.ThenwewouldusethealternativelightingshowninFigure6.5.
6.4ThemainlightpositionedsothatitfillsthefamilyofangleswemarkedinFigure6.3.
6.5AnalternativetothelightingshowninFigure6.4usesanopaquewhitereflectorcardandaspotlightfocusedtofillthefamilyofangles.
Aspotlightnearthecamera,withthebeamofthelightfocusedtoapproximatelyfillthefamilyofangles,wouldlightthesubjectidenticallytothelightthroughthediffusionsheet.
Mostsoftboxarrangementsdonotallowadjustmentofdistanceoftheheadtothediffusionmaterialonthefront.Thelightisfixedinsidetheboxtoilluminatetheentirefrontoftheboxasevenlyaspossible.However,wecanachieveasimilareffectbyattachingblackcardstothefrontofthesoftboxtolimititseffectivesize,asshowninFigure6.6.
Weusedthefirstofthesethreealternativestophotographabrightlypolishedmetalspatulaonawhitepaperbackground.Figure6.7istheresult.
Asweexpected,themetalisapleasinglightgray.Ifyouhaveneverlitascenethisway,youmightnothaveexpectedthephotographtorenderthe“white”backgroundsodark!Thisisanecessaryconsequenceofthelighting.Theexposureis“normal”forthisscene.
6.6AthirdalternativetothelightingshowninFigure6.4:asoftbox,withitseffectivesizeadjustedbyblackcards.
WhatIsa“Normal”ExposureforMetal?
BecausethemetalwastheimportantsubjectmatterinFigure6.7,weexposedtogetitrightandignoredthebackground.Howmightweexposethemetalto“getitright”?Onegoodwayisaspotmeterreadingonthemetal,rememberingtoexposetwotothreestopsmorethanthemeterindicates.(Themetertellsushowtoexposethemetaltobean18%gray.However,wewantitbrighterthanthat.
Justhowmuchbrighterisacreativedecision,notapurelytechnicalone.Twotothreestopsisareasonablerange.)
Keepinmindthatintheprecedingexample,welitthemetaltobeasbrightaspossiblewithoutbotheringwithanyotherconsiderations.Becausethemetalproducesalmostnothingbutdirectreflection,itsbrightnessintheimageapproximatesthatofthelightsource.Agraycardreflection
readingofthescenewillprobablynotpredictanacceptableexposureifthemetalistheimportantsubject.Thegeneralrulethattellsustoplacethemiddlegraysaccurately,lettingtheextremesfall
6.7Thebrightmetalspatulabladeisplacedagainstawhitebackground.Doyouknowwhythewhitebackgroundlookssodark?
wheretheymay,failswhentheimportantsubjecthappenstobeverymuchbrighterthanan18%graycard.Thus,the“proper”exposureforthisscenerendersthewhitebackgroundasadarkgray.
Suppose,however,thatthemetalisnottheonlyimportantsubject.Thiscouldhappeneveninthissimplescene.Therearenootherimportantobjectshere,butthewhitebackgroundcouldbecriticalinanadvertisementrequiringlegibleblacktypeintheimagearea.
Inthatcase,agraycardreadingwouldgiveanexcellentexposureofthewhitebackgroundbutattheexpenseofhopelesslyoverexposedmetal.Thereis,unfortunately,no“normal”exposurethatworksforboth.Ifthemetalandthewhitepaperarebothimportant,wehavetorelightthescene.Wewillsoonseeseveralwaystodoso.
KeepingtheMetalDark
Intheprevioussection,wetalkedabouthowtophotographmetaltoappearbright.Nowwewillrelightthescenetokeepthemetalasdarkaswecan.Inprinciple,nothingcouldbeeasier.Allwehavetodoistolightthemetalfromanydirectionweplease,otherthanfromwithin
6.8Thislightpositionisoneofthemanythatwouldworkifwewanttokeepthemetaldark.Theimportantpointistokeepthelightoutsidethefamilyofangles.
thatlimitedfamilyofanglesthatproducesdirectreflection.Onesimplewaytodothisistoputthelightnearthecamera.Wewillstartbyshowingwhathappenswhenwedo.
ThelightpositionshowninFigure6.8isoneofmanythatwouldwork.Notethatthesamefamilyofangleswedeterminedearliernowmarksthepositionswherewemustnotplacethelightifwewanttokeepthemetaldark.
Althoughthefamilyofanglesisstillinthediagram,noticethatthewhitetestsurfaceonwhichitwasmarkedisgone.Hadweleftitinplace,itwouldhavereflectedsomeofthegeneralillumination,behavingasanadditionallightsource.
Figure6.9provesthetheory.Itshowsgraphicallywhathappenswhenweplacethelightsourceoutsidethefamilyofanglesthatproducesdirectreflectionsonthemetalspatula.ThelightingsetupinFigure6.8cancauseonlydiffusereflection.Becausethemetalcannotproducemuchdiffusereflection,itisblack.Thepapercanproducediffusereflectionfromalightfromanydirection,soitisrenderedwhite.
6.9Thelightisoutsidethefamilyofanglesreflectedbythespatula.Withnodirectreflectionsonthemetalsurface,itisblackinthispicture.
Anincidentreading,agraycardreading,orareadingofthewhitepaper(withtheappropriatecompensation)wouldallbegoodexposureindicators.Thisistrueofalmostanyscenewithreasonablyevenilluminationandlittleornodirectreflection.Withneitherdirectreflectionnorimportantdarksubjectsinshadow,wedonothavetothinkabouttheextremes.Gettingthemiddlegraysexposedproperlyisallweneedtoworryabout.
WeareunlikelytousethelightinginFigure6.8astheprincipallightingofasceneexcepttodemonstratetheprinciple.Thepositionandthehardnessoftheshadowaretoodispleasing.Withthatinmind,wewillmovetoaslightlymoredifficultvariationonthesametheme.Wewillkeepthemetalsurfaceblackbutremedytheobjectionableshadow.
Assumethetesttargetweusedtofindthefamilyofangleswasmuchlargerthantheminimumneededtofillthoseangles.Ifwelightthesubjectwitheverypointonthesurfaceexceptthemarkedfamilyofangles,wewillhavealarge,softsourcethatstillkeepsthemetalblack.Figure6.10showshowwecanaccomplishthatresult.
Noticethatwehavebackedupourlighttoilluminatetheentirediffusionsheetasevenlyaspossible.Thenwehaveattachedagobocut
6.10Thelargelightlightsthescenesoftly,butthegobofillsthefamilyofanglesandkeepsthemetaldark.
toasizeandshapethatbarelyfillsthefamilyofangles.Figure6.11istheresult.
Thistechniquewouldalsoworkverywellusingasoftboxinsteadofaframeddiffusionsheetandalightonaboom,butitwouldbelesseffectiveusinganopaquewhitereflectorcard.Thelightilluminatingthereflectorcardwouldalsoilluminatethegobobrightly.Thegobowouldbehavemorelikeareflectorthanalight-blockingdevice,eventhoughitmightbeblack.Becausethatblackgobowouldabsorbsomephotonsandreflectothers,itwouldnotbeagoodwaytodemonstrateeitherbright-metalordark-metallighting.However,itmightbethemostpleasingcompromiseofall.
TheElegantCompromise
Wealmostneverusethebright-metalorthedark-metallightingtechniquesbythemselves.Moreoftenwepreferacombinationofthetwo,acompromisebetweentheextremes.
6.11Weusedagobotoblockthefamilyofanglesreflectedbythemetalwhenwetookthisshot.Thisdarkenedthespatula.
Figure6.12isacompromise.Itwasmadewithlightfillingthefamilyofanglesthatproducesdirect
reflectionfromthemetalplusilluminationfromotheranglestoproducediffusereflectionfromthebackground.
Figures6.13,6.14,and6.15showsomepossiblelightingarrangementsthatcouldhaveproducedthe
photograph.Everyarrangementuseslightfromwithinthefamilyofanglesandfromotherdirections.WeusedthelightinginFigure6.15,butanyoftheselightingarrangementscouldproduceequivalentresults.Thebestwayiswhateversuitstheequipmentyouhaveonhand.
Themostimportantpointbehindthisdemonstrationisnottoconvinceyouthatthecompromise
lightingmakesthebestpicture,buttogetyoutounderstandthethinkingthatleadsuptothecompromise.
Wecandecideexactlywherewewanttoplacethemetalonthegrayscale.Theprecisetoneofthemetalisfullycontrollable,independentlyoftherestofthescene,anditcanbeanystepbetweenblackandwhitethatthephotographer’screativejudgmentdetermines.
IfwehadusedthelightinginFigure6.13,forexample,wecouldhavemadethemetalbrighterbyincreasingthepowerofthelightabovethediffusionmaterial,orwecouldhavemadethepaperbackground
6.12AnelegantcompromisebetweenFigures6.7and6.9.Lightfillsthefamilyofanglesthatproducesdirectreflectionfromthemetal,andlightfromotheranglesproducesdiffusereflectionfromthebackground.
6.13OnewaytolightthespatulashowninFigure6.12.Themainlightispositionedwithinthefamilyofanglestoproducethelarge,bright,direct
reflectiononthespatula.Thefilllightbrightensthebackground.
6.14AnotherwaytolightthespatulashowninFigure6.12.Thegobopartlyblocksthelightfromthepartofthereflectorwithinthefamilyofangles,markedA,butnotfromtherestofthereflectorcard,markedB.
6.15Thepartofthesoftbox,B,outsidethefamilyofangles,
A,lightsonlythebackground,notthemetal.
brighterbyplacingamorepowerfulfilllightnearthecamera.Usingtwolightsinthismannergivesinfinitecontroloftherelativebrightnessofthemetalandthebackground.
Evenasinglelightprovidesexcellentcontrolifitislargeenough.LookagainatthesinglesoftboxinFigure6.15.Noticethattheentirelightsourceproducesdiffusereflectionfromthepaper,butonlythat
portionthatcoversthefamilyofanglesproducesdirectreflectiononthemetal.Havingmoreofthesurfaceofthesoftboxwithinthefamilyofanglesmakesthemetalbrighter.However,ifthesoftboxislargeenoughtohaveverylittleofitssurfacewithinthefamily,thenthebackgroundwillbebrighter.
Thedistancebetweenthelightsourceandthesubjectdetermineshowmuchofthatsourcewillbewithinthefamilyofangles.
ControllingtheEffectiveSizeoftheLight
Inpreviouschapters,wehaveseenthatcontroloverthesizeofthelightsourceisoneofthemostpowerfulmanipulativetoolsaphotographerhas.Wehavealsoseenthatthephysicalsizedoesnotnecessarilydeterminetheeffectivesize.Movingalightclosertothesubjectmakesitbehavelikealargerone,softeningtheshadowsand,forsomesubjects,enlargingthehighlights.Movingthelightfartherawaydoestheopposite.Thisprincipleisevenmoresignificantifthesubjectisbrightmetal.
InFigure6.16weseethesamecameraandsubjectrelationshipsusedearlier.Nowtherearetwopossiblepositionsforthesamesoftbox.Onepositionismuchclosertothesubjectthanthatusedinthepreviousexample,whereastheotherismuchfartheraway.
Weexpectthecloserlighttoilluminatethebackgroundmorebrightly,butthebrightnessofthemetaldoesnotchangebecausethebrightnessofdirectreflectionisnotaffectedbythedistancetothesource.Figure6.17confirmsthatexpectation.Movingthelightcloserhasgreatlylightenedthebackgroundwithoutaffectingthebrightnessofthemetal.CompareitwithFigure6.12,madewiththesamesoftboxfartheraway.Similarly,movingthelightfartherfromthesubjectwoulddarkenthebackground,stillwithoutaffectingthebrightnessoftheimageofthemetal.
Changingthedistanceofthelightsourcechangesthebrightnessofthebackgroundbutnotofthemetal.Thisseemstogiveusnearlyinfinitecontroloftherelativebrightnessofthetwo.Sometimesitdoes,butnotalways.Thisisbecausethefocallengthofthelenscanalsoindirectlyinfluencetheeffectivesizeofthelight.Thisisoftensurprising,eventohighlyexperiencedphotographers,butthediagramsinFigure6.18showhowitcanhappen.
n)6.17ComparethisphotographwithFigure6.12.Movingthesoftboxcloserhasbrightenedthebackgroundbutnotthespatula.
6.16Twopossiblepositionsforasoftbox.Eitherpositionlightsthemetalidentically.However,thecloserwemovethelighttothesubject,thebrighterthebackgroundbecomes.
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6.18Thedistancefromthesubjecttothecameraaffectstheeffectivesizeofthelight.CameraBisclose,andtheresultingfamilyofanglesislarge.CameraAisfartherfromthesubjectthanB,andtheresultingfamilyofanglesismuchnarrower.Ifthemetalisexposedidenticallyinthetwo
scenes,thebackgroundwillbebrighterinarrangementAanddarkerinB,despitethefactthattheactualincidentlightisidenticalinbothscenes!
A
InFigure6.18A,thecamerafartherfromthesubjecthasalongfocal-lengthlens,andtheclosercamera(B)hasashortlens.Therefore,theimagewillbethesamesizeineitherphotograph.
TocameraA,fartherfromthesubject,thesoftboxismuchlargerthanthefamilyofanglesthatproducesdirectreflection.Wecouldmovethelightmuchcloserormuchfartherawaywithoutaffectingthelightingofthemetal.Thelongerlens,byallowingamoredistantviewpoint,offersamoreflexiblechoiceofplacestoputthelight.Thus,itmaximizesthecontrolovertherelativebrightnessofthesubjectandthebackground.
ButlookatthedifferenceintheeffectivesizeofthelightseenbycameraB.Thesoftboxjustfillsthefamilyofanglesdefinedbythecloseviewpoint.Wecannotmovethelightmuchfartherawaywithouttheedgesofthemetalbecomingblack.
InChapter5wesawthatcameraviewpointalsodeterminesperspectivedistortion.Sometimesthereisnotmuchchoiceaboutwheretoputthecamera.Inotherscenes,thereisawiderangeofsatisfactorycamerapositions.Inthosecases,ifthesubjectisbrightmetal,werecommendusingalongerlensandgettingthecamerafartherawaytoallowmorefreedominlighting.
KeepingtheMetalSquare
Innoneoftheprecedingexampleswasthecameraperpendiculartothemetalsurface.Sometimesweneedaphotographinwhichthecameraviewpointappearstobeperpendiculartothemetalandcentereddirectlyinfrontofit.Becausethemetalisamirror,thecameraislikelytoreflectinthesubject.Nowwewillseeseveralwaysofdealingwiththisproblem.Youwillprobablyuseeachofthem
atonetimeoranother,dependingonthespecificsubjectandtheavailableequipment.
UseaViewCamera
Thisisthebestsolution.(Ifeveryoneusedviewcameras,wemightnotevenmentionanyothertechniques.)Aslongasthecamerabackisparalleltothereflectivemetal,themetalwillappeartobecenteredinfrontofthecameratomostviewers.
InFigure6.19,wepositionedthecameraoffcentersothatitdoesnotreflectinthemetal.Theimageplaneisstillparalleltothesubjectsotheviewpointdoesnotintroduceperspectivedistortion.Wethenshiftedthelenstocenterthesubjectintheimagearea,justasitwouldbeifthecameraweredirectlyinfrontofthesubject.Noticethatthisplacesthefamilyofanglestoonesideofthecamera.
6.19Thecamerawillnotreflectinthemetalbecauseitisoutsidethefamilyofangles.Themetalwillnotbedistortedbecauseitisparallelwiththeimageplane.
Alllightingtacticsdiscussedearlierareapplicable:weusealightlargeenoughtofillthefamilyofangles,keepthelightoutofthefamilyofangles,oruseacombinationofthetwo,dependingonhowbrightwewantthemetaltoappear.
Ifthecamerapositionrequiresshiftingthelensagreatdistanceoffcenter,wemayencountertwospecialproblems.First,thelensmaybegintovignettetheimage.Thiscreatesblackcornersattheedgeofthepicture.Second,viewingthesubjecttoofaroffcentercanproducegeometricdistortionorrevealtheslightdistortionthatcanbepresenteveningoodlenses.Keepingthecameraasfarfromthesubjectaspossible,andusingacorrespondinglylongerlens,minimizesbothoftheseproblems.
AimtheCamerathroughaHoleintheLightSource
Assumingwewanttokeepthemetalbright,wesometimespositionwhiteseamlesspapertolightthemetal.Wethencutaholeinthatlightsourcethatisjustlargeenoughforthelenstoseethroughit(Figure6.20).Thissolutionminimizestheproblemofcamerareflection,
6.20Thecamerawillnotreflectinthemetal,buttheholeinthepaperwill.
butitdoesnotgetridofit.Althoughthecameraisnotvisibleinthesubject,theholeinthelightsourceis.
Thistechniqueworksfineifthereisenoughirregularityinthemetalsubjecttocamouflagethe
offendingreflection.If,forexample,thesubjectisamachinewithacomplexcontrolpanel,reflectionmaybeinvisibleamongtheknobsandmeters.
Whetherthelightsourceisareflectorcardoradiffusionsheet,wehavetobeespeciallycarefulinlightingtheareanearthecamera.Alightaimedatareflectorcardcancauseflareiftheraysfalldirectlyintothelens.Lightsprojectingthroughadiffusionsheetcancauseashadowofthecameraonthediffusionsheetthatreflectsvisiblyinthesubject.
PhotographtheMetalatanAngle
Keepthecameraasfarfromthesubjectaspossibletominimizeperspectivedistortion.Thencorrectthedistortioninpostproduction.Digitallyremovingthedistortionisnotanidealsolution.Thissortofimagemanipulationalwaysresultsinsomequalityloss.
Keepthesesolutionsinmindasanavailableoptionifcircumstancesforceituponyou.Abadremedymaybebetterthannoremedy.Ifyouusethisalternative,besuretocomposeyourpicturewithagenerousamountofextraspacearoundthesubject.Youwillhavetocropthetrapezoidalprojectedimagetofittherectangularprint.
RetouchtheReflection
Shootthemetalstraighton,letthecamerareflect,thenremovethereflectiondigitally.Thisisnotalightingsolution,sowewillnotdiscussitindetail.Nevertheless,forsomesubjects,especiallylargeones,retouchingissomucheasierthananyofthelightingsolutionsthatweshouldnotforgettheoption.Spendinghalfadaylightinginsteadofspendinghalfanhouratacomputermakesnosense.Furthermore,thissolution,unliketheimmediatelyprecedingone,losesnoimagequality.
METALBOXES
Ametalboxpresentstheviewerwithuptothreevisiblesides.Eachsideneedsatreatmentsimilartothatofanyotherflatpieceofmetal.Eachsurfacehasitsownfamilyofanglestoconsider.Thedifferenceisthateachfamilyofanglesfacesadifferentdirectionandwehavetodealwiththemallatonce.
Inlightingametalbox,weneedtodealwithsomeofthesameconsiderationsinvolvedwithlightingaglossyboxmadeofanyothermaterial.(Ifyouarebrowsingthroughthisbookwithoutreadingthechaptersinsequence,youmaywanttolookatthesectiononglossyboxesinChapter4.However,althoughthistheoryisidenticaltothatappliedintheearlierpicture,thedifferencemakesuslikelytoapplyittheoppositewayfromthatintheearlierexample.)
Figure6.21isidenticaltoFigure5.19,repeatedheresothatyoudon'thavetokeepturningbacktoit.Now,however,theboxismadeofmetal,notwood.Therearetwofamiliesofangles,oneforthetopandoneforthefrontofthebox.Wemayplacelightwithinthesefamiliesofangles,ornot,dependingonwhetherwewantthesurfacestobebrightordark.Iftheboxwereturnedtoshowthecamerathreesides,thesameprincipleswouldapply—buttheywouldbehardertoseeinadrawing.Thefamilyof
anglesdefinedbythefrontoftheboxwouldthenfallbelowandtothesideofthebox.Theothervisible
sideoftheboxwouldproduceasimilarfamilyofanglesontheothersideofthescene.
Aglossynonmetallicboxthatisnotblackproducesbothdiffuseanddirectreflection.Weoftenavoiddirectreflectiononaglossyboxtoavoidobscuringthediffusereflection.Apolishedmetalboxproducesonlydirectreflection.Withoutdirectreflection,weseethemetalboxasblack.
6.21Twofamiliesofanglesofaboxpositionedsothatthecameracanseebothitstopandfront.
Becausewemoreoftenliketorendermetalbright,weusuallywanttocreatedirectreflectionratherthantoavoidit.Thismeansthatweneedtofilleachfamilyofangleswithalightsource.
Thefamilyofanglesdefinedbythetopoftheboxiseasytolight.Wetreatitjustaswedidtheflatmetalinourearlierexamples.
Thesidesofametalboxaremoredifficult.IfwepositionthecameraandsubjectasinFigure6.21,then
atleastoneofthelightsourcesmustbeinthepicture.Thefamilyofanglesdefinedbythefrontoftheboxfallsonthetablewheretheboxsits.Thatmeansthetablesurfaceisthelightsourceforthefrontofthebox,whetherwelikeitornot.
Wecannotuseareflectorcard,oranyotherlightsource,forthesidesoftheboxwithoutitshowinginthescene.Theclosertotheboxwecancropthepicture,thecloserwecanputthereflector.Evenso,someofthebottomoftheboxwillstillreflectthetable.
Ifwedonotwanttocropthebottomoftheboxoutoftheimage,andiftheboxistrulymirror-like,thelinewherethereflectormeetsthetablewillbevisibleandobjectionable.Figure6.22showstheproblem.Wehaveleftthepictureuncroppedsothatyoucanseethereflectorcard.
6.22Thebottomoftheboxdisappearsintothedarktable.Theonlywaytopreventthiswouldbetoplacethereflectorsothatittouchesthefrontofthebox.
Brightlypolishedmetalboxesalmostalwayspresentthisproblem.Fortunately,itisusuallytheonlymajorproblem;theremainderofthissectionisacollectionoftechniquesfordealingwithit.Picktheoneyouneedaccordingtothecircumstance.
ALightBackground
Byfartheeasiestwaytophotographathree-dimensionalmetalsubjectistousealight-graybackground.Thebackgrounditselfisthelightsourceformuchofthevisiblemetal.Assoonasweplacethesubjectonsuchasurface,muchoftheworkisdoneandweneedonlyafewadjustmentstoperfectthelighting.
ToproduceFigure6.23,webeganwithabackgroundsurfacelargerthanweneededtofilltheimagearea.Rememberthatthebackgroundneedstofillthefamilyofanglesreflectedbythemetal,notjusttheareathecamerasees.Thenwelitthetopofthemetalboxwithasoftbox,justasifitwereanyotherpieceofflatmetal.
Thatwasalmostallwehadtodo.Thesetupwascompletedbysilverreflectorsoneachsideofthescenetofilltheshadowintheribbon.
6.23Thelightgraysurfaceonwhichwephotographedthisboxactedasalightsourceforthefrontofit.
Ifgoodlightingforthemetalboxweretheonlyobjective,wewouldalwaysusealight-tonedbackground.Artandemotionoftenimposeotherrequirements,however,sowewilllookatsomeothertechniques.
ATransparentBackground
Theonlywayinwhichwecanorientametalboxaswedidinthepreviousexampleswithouthavingalightsourceinthesceneistoputtheboxonatransparentsurface.Whenwedothat,thecameraseesthereflectionofalightsource(inthiscase,awhitecard)inthemetalwithouthavingthatlightsourceindirectviewofthecamera.Figure6.24showshow.
Thisarrangementallowsustopositionadarkcardlargeenoughtofillthebackgroundbutsmallenoughthatitstaysoutofthefamilyofanglesthatlightsthefrontandthesideofthemetalbox.ThephotographinFigure6.25wasmadethisway.Noticethatthebackgroundisdark,butnotblack,andthatthetablesurfacehasareflectioninit.Fromthisviewpoint,anylightsourceproducingdirectreflectionontopofthemetalwillalsocreatedirectreflectionontheglasssurfacesupportingit.
Thepictureisgood.Butsupposewedislikedthereflectionintheglassandwantedthebackgroundtobeabsolutelyblack.Wecould
6.24Onewayoflightingthefrontofametalboxwithouthavingalightsourceinthescene.Placingtheboxonasheetofclearglassallowsreflectinglightthroughtheglasstothebox.
eliminatethereflectionoftheboxbyusingfrostedglass,butthatwouldmakethebackgroundlighterinsteadofdarker.
Fortunately,mostofthedirectreflectionfromglassviewedatthisangleispolarized,sowewereabletoeliminatethatreflectioninFigure6.26byputtingapolarizingfilteronthelens.Theglassisnowblack.Remember,too,thatdirectreflectionfrommetalisneverpolarizedunlessthelightsourceitselfispolarized.Sothepolarizingfilterdidnotblockthedirectreflectionfromthemetal.
AGlossyBackground
Ifthemetalisonaglossysurface,itispossibletohavethelightsourceintheimageareawithoutthe
cameraseeingit!Wecallthistechniqueinvisiblelight.Hereishowitworks:lookbackatFigure6.21,butthistimeassumethesubjectissittingonaglossyblackacrylicsheet.Thefamilyofanglesdefinedby
thefrontsurfacetellsusthattheonlypossibleplacefromwhichthemetalcouldgetlightwouldbefromtheblackplastic
6.25TheresultofthelightingshowninFigure6.24.Whetherthedarkreflectionundertheboxisobjectionabledependsonthespecificsubjectandyouropinionofit.
6.26ThesamesceneasinFigure6.24,butwithalenspolarizerremovingreflectionfromtheglass.Thepolarizerdoesnotaffectthemetal.
6.27“Invisible”lightreflectedfromtheglossyblackplasticlightsthemetal.Nolightreflectsdirectlyfromtheplastictothecamera,sothecameracannotseethelightsourceforthemetal.
surface,but“black”isashortwayofsayingthattheplasticreflectsnolight.Together,thesefactssuggestthatthefrontofthemetalcannotbelit.
However,wehavealsosaidthattheblackplasticisglossy.Andweknowthatglossythingsdoproducedirectreflection,eveniftheyaretooblacktoproducediffusereflection.ThismeansthatwecanlightthemetalbybouncinglightofftheplasticsurfaceasinFigure6.27.
Ifyouexaminetheangles,youseethatalightunderthecameracanbouncelightfromtheglossyplastictothemetal.Thatlightstrikesthemetalatsuchananglethatitthenreflectsbacktothecameratorecordonfilm.Themetalislit,andthebrightmetalinFigure6.28provesit.Asfarasthemetalcantell,itisbeinglitbytheplasticsurfaceinthescene.However,thecameracannotseethatlightisreflectingfromtheblackplastic;thefamilyofanglesdefinedbytheplasticmakesitimpossible.
Liketheearlierglasssurface,theacrylicsurfacewillreflecttheoverheadlightsource.Onceagain,weusedapolarizingfilteronthelenstoeliminatetheglare.
6.28Theresultof“invisible”light.Thelightsourcefortheboxisinthescene—theblackplasticdirectlyinfrontofit.
Finally,noticethatthefrontoftheboxnowshowsatexturenotseenintheearlierexamples.Thisisbecauseinvisiblelightisonlyeffectiveinasmallareaonthetabletop.
Whenmetalisnotabsolutelyflat,thefamilyofanglesrequiredtolightitbecomeslarger.Nextwe'llexamineanextremeexampleofthatcircumstance.
ROUNDMETAL
Lightingaroundpieceofmetalbegins,likeanyothermetalshape,withananalysisofthefamilyofanglesthatproducesdirectreflection.Unlikeanyothermetalshape,thefamilyofanglesdefinedbyapieceofroundmetalincludespracticallythewholeworld!
Figure6.29showstherelevantfamilyofanglesforacameraphotographingaroundmetalobjectatatypicalviewingdistance.Remember,lightingmetalrequiresthepreparationofasuitableenvironment.Roundmetalrequiresalotmoreworktolightbecauseitreflectssomuchmoreofthatenvironment.
Noticethatthecamerawillalwaysbeintheenvironmentthemetalsees.Therearenoview-cameratrickstoremovethecamerafromthe
6.29Thefamilyofanglesforaroundmetalsubjectconsistsofitswholeenvironment,includingthecamera.
familyofanglesreflectedbyroundmetal.Furthermore,thereflectionofthecamerawillalwaysfallexactlyinthecenterofthemetalsubject,whereitismostnoticeabletotheviewer.
Forthisexercisewewillusethemostdifficultexamplepossible:aperfectlysmoothsphere.Figure6.30showstheproblem.
Thefirststepinfixingthisproblemwouldbetogetridofunnecessaryobjects.However,thecameraistheoneoffendingobjectthatnocleanupeffortcanremove.Therearethreewaystoeliminatethecamerareflection:wecancamouflagethereflection,keepthecamerainthedark,orputthesubjectinatent.
Camouflage
Forourpurposes,camouflageisanydesirableclutterthathelpsmakeunwantedreflectionslessobvious.Sometimesthesubjectprovidesitsowncamouflage.Ifthesurfaceisirregular,thecamerareflectionmayfallbetweenthecracks.
Additionalsubjectsinthescenecanalsoprovidecamouflage.Thereflectionofsurroundingsubjectsinthemetalcanbreakupother
6.30Thecommonproblempresentedbyashinysphere.
reflectionsthatwedonotwanttheviewertosee.IfthesurroundingobjectsinFigure6.30wereitemsappropriatetothescene,insteadofstudiotools,theycouldmakegoodcamouflage.Smallsubjectscanbeputdirectlyontopofareflectionofalargerone.
KeepingtheLightofftheCamera
Ifthecameraiskeptinthedark,thenitcannotseeitselfreflectedinthesubject.Wheneverpossible,confinethelightingtothesubject.Longlenseshelp.Acamerafartherfromthesubjectislesslikelytohaveextraneouslightfallingonit.
Ifitisimpossibletokeepthelightoffthecamera,coveringitwithblackmaterialcanworkaswell.AfewpiecesofblacktapecouldhavecoveredthebrightpartsofthecamerainFigure6.30.Blackclothorablackcardwithaholeinitcanconcealthecameraentirely.
However,thisworksonlyinastudiolargeenoughthatthesurroundingwallsdonotreflect.Inasmallerroom,buildingatentmaybetheonlysolution.
UsingaTent
Atentisawhiteenclosurethatservesasboththeenvironmentandthelightsourceforthesubject.Thesubjectgoesinsidethetentandthecameraisalmostalwaysoutside,lookinginthroughasmallopening.Tentsareoftenusedforsubjectssuchasmetal,whichproduceagreatdealofdirectreflection,buttheyaresometimesusedsimplytoproduceverysoftlightforsubjectssuchasscientificspecimensandforfashionandbeauty.
Atentcanbemadeofopaquewhitematerialsuchasacollectionofreflectorcards.Thenwecanput
thelightsinthetentandbouncethemofftheinsidewalls.Thisproducesaverysoftlight,butthelightsthemselvesreflectvisiblyinanymirror-likesubject.Moreoftenweusetranslucentmaterialsuchasfrostedplasticandprojectthelightsthroughthetentwall.
Anidealtentwouldbeatranslucentwhitedomewithnovisibleseams.Mostphotographersapproximatethisidealascloselyaspossiblewithtranslucentpaperorplastic.Figure6.31showsonewaytodothis.
Wedonotshowanylightsotherthanthesoftboxthatisastructuralpartofthistent.Additionallightsarealmostalwaysuseful,buttheirexactpositionsandsizesarehighlyoptional.Somephotographersliketolightthewholetentuniformly,whereasotherstendtolightonlyafewsmallareas.
Figure6.32wasshotinsuchatent.Thisphotographisagoodexampleoftheprinciple,butitisabadpicture.Thelightingontheballisacceptable,exceptforthedarkspotinthemiddle,whichistheholethroughwhichthecameraisseeing.
OneoftheauthorsoncemadeapicturesimilartothisoneforthecoverofadepartmentstoreChristmascatalog.Buttheperipheralareasalsoincludedbitsofribbonandgreenerytocamouflagetheseamsinthetent.
Loopingapieceoftheribbon“accidentally”acrossthefrontoftheballhidthecamera.Iftheintentoftheimagehadprecludedadditionalsubjectmattertouseforcamouflage,theonlyremedytotheproblemwouldhavebeenretouching.
Itistemptingtobuildaverylargetenttokeepthecameraasfarfromthesubjectaspossible.Intuitivelyweknowthatifthecameraisfartherfromametalsubject,thenthereflectionofthecamerawillbesmaller.However,theimageofthesubjectalsobecomessmaller,sowehavetoshootwithalongerlens.Butthis“remedy”alsoenlargesthereflectionofthecamerabacktoitsoriginalsize!Thecameraitselfisthe
6.31Buildingatentaroundthesubjectandshootingthroughaholeinitisonewayofcuttingdownonunwantedreflectionsonshinyroundsubjects.
6.32Aphotographofashinysphereshotwiththehelpofatentsuchastheonediagrammedinthepreviousfigure.
Byitself,thetentdoesnotsolvetheproblems.However,itwillmakeanyretouchingeasier.
onlyreflectionwhosesizecannotbereducedbymovingitfartheraway.Italwaysremainsconstant,relativetothesubject.Resistthetemptation;theextraworkisalwayswasted.
OTHERRESOURCES
Thebasicapproachtolightingmetalisdeterminedbythefamilyofanglesand,therefore,bytheshapeofthemetal.Beyondthebasiclighting,thereareafewmoretechniquesyoumaywanttotryatanytimewithanypieceofmetal.
Anyoftheseadditionaloptionscanbepurelycreativedecisions,buttheycanservetechnicalpurposes,too.Forexample,youmayfindthattheedgeofapieceofmetalisdisappearingintothebackground.
Keepinmind,thecloserthemetalcomestoproducingpuredirectreflection,thecloserthatreflectioncomestophotographingatthesamebrightnessasthelightsource.Aswehaveseen,thesurfaceonwhichthemetalissittingisoftenthelightsource.Iftheyareofidenticalbrightness,thecameracannotseewhereonesurfaceendsandtheotherbegins.Thisisacasewherepolarizingfilters,“blackmagic,”ordullingspraycanaddthefinishingtouchestothelighting.
PolarizingFilters
Metaldoesnotproducepolarizeddirectreflections.Therefore,wecannotusuallyusealenspolarizeralonetoblockthedirectreflectionscomingfrommetal.Remember,however,thatthelightsourcemayhavesomepolarizedrays.Ifso,theyremainpolarizedastheyreflectfromthemetal.Thisisfrequentlythecaseifthemetalisreflectingbluesky.Inthestudio,thelightreflectedfromthesurfaceonwhichthemetalrestsisoftenpartlypolarized.Ineithercase,apolarizeronthelensgivesadditionalcontroloverthebrightnessofthemetal.Evenifthereisnopolarizedlightinthescene,wecanputittherebyusingapolarizingfilteroverthelight.
BlackMagic
Blackmagicisanythingaddedtothebasiclightingsetupsolelytoplaceablack“reflection”inthemetalsurface.Blackreflectedinanedgecanhelptodifferentiateitfromthebackground.Reflectedacrossthecenterofaslightlyirregularsurface,blackmagiccanalsoadddimension.
Blackmagicusuallyinvolvestheuseofagobo.Thisworksespeciallywellwithadiffusionsheet.Placingthegobobetweenthediffusionsheetandthesubjectmakesahardblackreflection.Puttingitontheothersideofthediffusionsheetfromthesubjectcreatesasoftlygraduatedreflection.Thefartherbehindthediffusionsheetyouplacethegobo,thesofteritbecomes.
Occasionallyyoumaydecidetouseanopaquereflector(reflectinganotherlightsomewhereelseintheset)asalightsourceforthemetal.Inthiscase,agobocannotproducesoftlygraduatedblackmagic,butasoft-edgedstripeofblackspraypaintacrossthereflectorwillcreatethesameeffect.
BewareofBlueHighlights
Polarizingboththelightsandthelensmaycreatespecialproblemsifthephotographiscolorandthesubjectismetal.Polarizingfiltersallowmore
lightfromtheblueendofthespectrumtopassthroughthanfromthered.Thismakessuchafilterbehavelikeaverylightbluefilter.Theeffectisso
slightthatwedonotnoticethecolorimbalanceinacolorphotographunlessextremelyaccuratecolorrenditionisnecessary.
Evenwhentherearepolarizingfiltersonboththelensandthelights,theincreasedblueshiftisrarelyaproblemifthesubjectproducesmostly
diffusereflection.However,ifthesubjectproducesmuchdirectreflection,someofthehighlightsmaybeoffensivelyblue.Furthermore,becausethe
blueoccursonlyinthehighlights,theycan’tbefixedbygeneralcolorcorrection.
Itiseasytooverlookthesebluehighlightsifyoudonotanticipatethem,sobewarned.Iftheyhappenandyoudecidethesacrificeisworthwhile,
budgetthetimeforretouching.
DullingSpray
Dullingspraycreatesamattesurfacethatincreasesthediffusereflectionanddecreasesthedirectreflectionfromapieceofmetal.Thisallowsalittlemorefreedomtolightthemetalwithoutstrictlyobeyingthelimitationsimposedbythefamilyofangles.Unfortunately,metalwithdullingsprayonitnolongerlooksbrightlypolishedandmaynotevenlooklikemetalanylonger!
Heavy-handeduseofdullingsprayisahabittoavoid.Toaneducatedeye,itreveals,ratherthanconceals,aphotographer'sinabilitytolightmetalwell.Withthatsaid,weshouldalsoadmitthatalloftheauthorsofthisbookkeepdullingsprayhandyintheirstudios.
Trytolightthemetalaswellaspossible.Then,ifnecessary,addalittledullingsprayjusttoanoverlybrighthighlightoradisappearingedge.Keepasmuchofthegleamofthemetalasyoucan,andavoidthicklycoatingtheentiresurface.
WHEREELSEDOTHESETECHNIQUESAPPLY?
Thetechniquesweuseformetalaregoodtorememberanytimedirectreflectionisimportant.Wewillseemoreofthemintherestofthisbook.Someoftheseapplicationsmaynotbeobviousyet.Forexample,
wewillseeinthediscussionofextremesinChapter9whymuchofthetechniqueforlightingmetalisusefulforalmostanyblack-on-blacksubject,regardlessofthematerialofwhichitismade.
Othersubjectsthatproducedirectreflectionarereadilyapparent.Oneofthemisglass.Glass,however,offersadditionalopportunitiesandchallengesofitsown.Wewillseewhyinthenextchapter.
7
TheCaseoftheDisappearingGlass
Thedistantgeniuswhofirstfusedsandintoglasshastrickedtheeyesanddelightedthebrainsofeverygenerationofhumanstofollow.Ithasperhapsalsograyedthehairandwastedthetimeofmorephotographersthananyothersubstance.However,attemptingtoreproducetheappearanceofglassneednotleadtothephotographicdisasterswesooftensee.Thischapterdiscussestheprinciples,theproblems,andsomestraightforwardsolutionstothebasicchallengesthatglassoffers.
THEPRINCIPLES
Theappearanceofglassisdeterminedbymanyofthesameprincipleswediscussedintheprecedingchapteronmetal.Likemetal,almostallreflectionproducedbyglassisdirectreflection.Unlikemetal,however,thisdirectreflectionisoftenpolarized.Wemightexpectthetechniquesusedforlightingglasstobesimilartothoseusedformetal.Wemightfindapolarizingfilterusefulmoreoften,butotherwiseapplythesamemethods.
However,thisisnotso.Whenwelightmetal,weareprimarilyinterestedinthesurfacesfacingthecamera.Iftheylookright,thenminoradjustmentscanusuallytakecareofthedetails.Lightingglass,however,requiresattentiontotheedges.Iftheedgesareclearlydefined,wecanoftenignorethefrontsurfacealtogether.
THEPROBLEMS
Theproblemscausedbyglasswarearearesultoftheverynatureofthematerial.Itistransparent.Frommostangles,lightstrikingthevisibleedgeofapieceofglasswaredoesnotreflectinthedirectionoftheviewer.Suchanedgeisinvisible.Aninvisibleglasshasnoshapeorform.Tomakemattersworse,thefewtinyreflectionswedoseeareoftentoosmallandtoobrighttotelltheanythingaboutsurfacedetailortexture.
Figure7.1showsbothproblems.Thedirectreflectionsofthelightsilluminatingthescenedonothingbutdistractfromthecomposition.Theyarenotadequatetodefinethesurfaceoftheglass.
7.1Theproblemswiththispicturearecausedbythenatureoftheglassfromwhichthesubjectsaremade.Theglassisbothtransparentandhighlyreflective.
Thelackofaclearlydefinedformisanevenmoreseriousproblem.Withnoclearoutlinesandnomarkeddifferencesinedgetonality,theglassmergeswiththebackground.
THESOLUTIONS
Havingseenwhatdoesnotwork,looknowatFigure7.2.Comparethevisibilityoftheglassshowninitwiththatshownintheearlierphotograph.Bothphotographsshowthesameglasswareandthesame
7.2Goodedgedefinitionisessentialtolightingglass.
159
background,andbotharemadefromthesameviewpointwiththesamelens.Asyoucansee,however,thedifferenceisdramatic.
Inthesecondphotograph,strongblacklinesdelineatetheshapeoftheglass.Nodistractingreflectionsmarthesurface.Bycomparingthesetwophotographs,wecanlistourobjectivesinglasswarephotography.Ifwewanttoproduceapicturethatclearlyandpleasinglyreproducestheglassware,wemustdothefollowing:
1.Producestronglinesalongtheedgesofthesubject.Theselinesdelineateitsshapeandsetitapartfromthebackground.
2.Eliminatedistractingreflectionsofthelightsandotherequipmentweareusing.
Let'slookatsomeofthespecificwayswecanaccomplishtheseobjectives.Wewillbeginbylookingatsome“ideal”shootingsituations.Thesewillhelpusdemonstratethebasictechniques.Later,wewillhavetogobeyondthosebasicstoovercomeproblemsthatarisewhenevernonglassobjectsareinthesamescene.Wewillbeginbytalkingaboutourfirstobjective,edgedefinition.
TWOATTRACTIVEOPPOSITES
Wecanavoidalmostalltheproblemsassociatedwithedgedefinitionbyusingoneoftwobasiclighting
arrangements.Wewillcallthesethebright-fieldandthedark-fieldmethods.Wecouldalsocallthemdark-
on-lightandlight-on-darkapproaches.
Theresultsofthesetwoareasoppositeasthetermsimply,butwewillseethattheprinciplesguidingthemareidentical.Bothmethodsproducethestrongtonaldifferencesbetweenthesubjectandthebackgroundthatdelineateedgestodefinetheshapeofglassware.
Bright-FieldLighting
Figure7.2isanexampleofthebright-fieldapproachtolightingglass.Thebackgrounddictateshowwemusttreatanyglasssubject.Onabrightbackground,wehavetokeeptheglassdarkifitistoremainvisible.
IfyouhavereadChapter2andthechaptersfollowingit,youhavealreadyguessedthatthebright-fieldmethodrequireseliminatingalldirectreflectionfromtheedgeoftheglasssurface.Youalsoshouldbeabletoseewhyweneedtobeginthisdiscussionbyexaminingthefamilyofanglesthatdeterminesdirectreflectionfromthisparticularsubject.
LookatFigure7.3.Itisabird’s-eyeviewofthefamilyofanglesthatcanproducedirectreflectiononasingleroundglass.Wecoulddrawasimilardiagramforeachpieceofglasswareinourexamplephotograph.
7.3ThelimitsofthefamilyofanglesinthisdiagramaremarkedbyL.Lightfromthesetwopointsdeterminestheappearanceoftheedgeoftheglass.
Thefamilyofanglesinthisdiagramissimilartothatdefinedbyroundmetalinthepreviouschapter.Thistime,however,wearenotinterestedinmostofthatfamily.Fornow,wecareonlyabouttheextremelimitsofthefamilyofangles,labeledLinthediagram.
Lightfromthesetwoanglesdeterminestheappearanceoftheedgeoftheglass.
Theselimitstelluswherethelightmustbeiftheedgesoftheglassaretobebrightinthepicturesor,conversely,whereitmustnotbeiftheedgesaretoremaindark.Becauseinthebright-fieldapproachwedonotwanttheedgeoftheglasstobebrightinthephotograph,there
mustbenolightalongthelinesmarkedLinthediagram.161
DarkBackgroundorNoBackground
Visible
Background
Glass
Subject
Light
forOpaqueBackground
Light
forTranslucentBackground
DarkBackgroundorNoBackground
7.4Thisisonewaytoproducethebright-fieldilluminationusedinFigure7.2.Wewouldrarelyusebothlightsshown.Eitherlightingpositionworks,dependingonthebackground.
Figure7.4illustratesonegoodwaytoproduceabright-fieldglassphotograph.Itisnottheonlyway,butitisagoodexercisethatwesuggestyoutryifyouhavenotdoneitbefore.Lookatthewaythelightbehavesineachstep.Thiswillmakeiteasytopredictwhatwillworkandwhatwillnotinanyvariationonthisarrangementyoudecidetotryinthefuture.
Thesestepsworkbestinthelistedsequence.Noticethatwedonotbothertoputthesubjectintothesceneuntilneartheendoftheprocess.
ChoosetheBackground
Beginbysettingupalight-tonedbackground.Wecanuseanyconve—162nientmaterial.Translucentmaterialssuchastracingpaper,cloth,and
plasticshowercurtainsareafewgoodmaterialstotry.Wemightalsouseopaquesurfaces,suchaslight-tonedwalls,cardboard,orfoamcore.
PositiontheLight
Now,placealightsothatitilluminatesthebackgroundevenly.Figure7.4showstwopossiblewaystoaccomplishthis;bothcanproduceidenticalresults.Usuallythephotographerusesoneortheother,rarelyboth.
Figure7.2wasshotusingalightbehindtranslucentpaper.Thisisaparticularlyconvenientsetupbecauseitkeepstheworkspacearoundboththecameraandthesubjectfreeanduncluttered.
Wecanalsouseanopaquesurfacesuchasawallforthebackground.Ifwedo,weneedtofindaplacetopositionthelightsothatitwilllightthebackgroundwithoutreflectingintheglassorappearingintheimagearea.Puttingthelightonashortstandbehindandbelowtheglassisonegoodway.
PositiontheCamera
Now,placethecamerasothatthebackgroundexactlyfillsitsfieldofview.Thisstepiscriticalbecausethedistancefromthecameratothebackgroundcontrolstheeffectivesizeofthebackground.
Theeffectivesizeofthebackgroundisthesinglemostimportantconsiderationwhenusingthistechnique.Forthisexercisetobemosteffective,thebackgroundmustexactlyfillthefieldofviewofthecamera,nomoreandnoless.
Abackgroundthatistoosmallisanobviousproblem:itsimplywillnotfillthepicture.Alargerbackgroundcausesasubtlerproblem.Abackgroundtoolargewillextendintothefamilyofanglesthatproducesdirectreflectionontheedgeoftheglass.Lightfromthosepointseliminatesthedarkoutline
thatweneedtodefinetheedgeoftheglass.
Ifthebackgroundsurfaceissolargethatwecannotkeepitfromextendingbeyondthelimitsoftheviewfinder(e.g.,thewallofaroom),wecanalsoreduceitseffectivesizebylightingonlyasmallportionofitstotalsurfaceorbycoveringpartofitwithdarkcards.
PositiontheSubjectandFocustheCamera
Next,movethesubjectbackandforthbetweenthecameraandthebackgrounduntilitisthedesiredsizeintheviewfinder.
Aswemovethesubject,wenoticethatthecloseritistothecamera,themoreclearlytheedgesaredefined.Thisincreaseinedgedefinitionisnotbroughtaboutbythesimpleprinciplethatlargerdetailiseasiertosee.Rather,itiscausedbythefactthatasthesubjectmovesfartherfromthelightedbackground,lesslightreflectsoffitsedges.Thecloserthesubjectistothebackground,themorethebrightbackgroundfallswithinthefamilyofanglesthatproducesdirectreflectiontoobscurethoseedges.
Now,focusthecameraonthesubject.Refocusingwillslightlyincreasetheeffectivesizeofthebackground,butthatincreasewillusuallynotbeenoughtocauseanypracticalproblems.
ShootthePicture
Finally,useareflectionmeter(theonebuiltintomostcamerasisfine)toreadthelightonanareaonthebackgrounddirectlybehindthesubject.
Bright-fieldilluminationdoesnotrequireapurewhitebackground.Aslongasthebackgroundisanytonesignificantlybrighterthantheedgesoftheglass,thenthatglasswillbeadequatelyvisible.Iftheglassistheonlysubjecttoworryabout,wecancontrolthebrightnessofthebackgroundbythewayweinterpretthemeterreading:
•Ifwewantthebackgroundtoappearasamedium(18%)gray,weusetheexposurethatthemeterindicates.
•Ifwewantthebackgroundtophotographasalightgraythatapproacheswhite,weincreasetheexposureuptotwostopsmorethanthemeterindicates.
•Ifwewantthebackgroundtobedark,thenweexposeasmuchastwostopslessthanindicated.Thiswillproduceaverydarkgraybackground.
Inthisscenethereisnosuchthingas“correct”exposure.Theonlycorrectexposureistheonethatwelike.Wecanplacethetoneofthebackgroundanywherewelikeonthegrayscaleexceptblack.(Iftheedgeoftheglassisblackandthebackgroundisblack,thereisnothinglefttorecord!)Inpractice,thelighterthebackground,themoregraphicallytheglassisdefined.
•Ifwedoexposetokeepthebackgroundverylight,wedonothavetoworryaboutextraneousreflectioninthefrontsurfaceoftheglass.Whateverreflectionsexistarealmostalwaystoodimtobe
visibleagainstthebackground.However,ifwedecidetoexposetoproduceamediumordarkgraybackground,surroundingobjectsmayreflectvisiblyintheglass.Wewilloffersomewaystoeliminatethesereflectionslaterinthischapter.
Inprinciple,thereisnothingparticularlycomplicatedaboutthebright-fieldapproachtophotographingglassware.Ofcourse,wehaveusedan“ideal”exampletodemonstratetheprincipleasclearlyaspossible.Inpractice,complicationsmayoccurwheneverwedecidetodeviatefromthisideal.
Forexample,manycompositionswillforceustokeeptheglassmuchsmaller,comparedwiththebackground,thaninourexercise.Thatwillreduceedgedefinition.Whetherthesacrificewillbesignificantdependsonwhatelseisinthephotograph.
Ofcourse,understandingtheprincipleandbecomingfamiliarwithwhytheidealworksgivesustheunderstandingthatprovidesthebestsolutioninlessthanidealsituations.Ifacompositionproducesbadlighting,theidealexplainstheproblemandsuggestsaremedy.Ifaparticularcompositionpreventsanyremedy,thentheidealtellsusthat,too.Weneednotwastetimetryingtoaccomplishwhatphysicssaysisimpossible.
Dark-FieldLighting
Thedark-fieldmethodproducestheoppositeresult,illustratedinFigure7.5.
ReviewthefamilyofanglesthatproducesdirectreflectioninFigure7.3.Wesawthatinthepreviousarrangementtheremustbenolightatthelimitsofthefamilyofangles,L,iftheedgeoftheglassistoremaindark.Itmakessensetosuppose,then,thatthelightmustcomefromLiftheedgeoftheglassistobebright.Furthermore,ifwedonotwantotherbrightdistractionsintheglass,thentheglassmustnotseelightatanyotherpoint.
Figure7.6showsthespecificstoputthetheorytowork.Onceagain,wewillpresentthetechniqueinfivesteps.Someofthemareidenticaltothoseusedintheearlierbright-fieldapproach.
SetupaLargeLightSource
Onfirstexamination,thebird's-eyeviewinFigure7.3seemstoindicatetheneedforlightattwopoints.This,however,isarepresentationaldefectcausedbyhavingtodrawinonlytwodimensions.Inactuality,suchanarrangementwouldlightonlyapointoneachsideoftheglass.
Tokeeptherimbright,asimilarlightsourcemustbeplacedaboveandbehindtheglass.Furthermore,iftheglassisastemmedglasswithabowl,thenyetanotherlightsourcemustbeaddedtoilluminatethebottomofthatbowl.
7.5Indark-fieldillumination,shapeandformaredelineatedbylightlinesagainstadarkbackground.
Soweneedfourlargesourcestolightjusttheedgesofasingletinyglass!Thisarrangementwouldbeunwieldyatbest.Weusuallyavoidsuchacomplexclutterbyreplacingalloftheselightswithasinglesourcelargeenoughtoilluminatethetop,bottom,andsidesoftheglass.Theexactsizeofthislightsourceisnotcritical.Anysizebetween10and25timesthediameterofthesubjectwillworkwell.
Figures7.6and7.7showtwogoodwaystocreateanappropriatelylargelightsource.Oneistranslucentandtheotherisopaque.
SetupaDarkBackgroundSmallerThantheLightSource
Thereareseveralwaystodothis.Theeasiestway,showninFigure7.6,istoattachadarkcarddirectlytothetranslucentlightsource.
7.6Thisisonegoodwaytoproducedark-fieldlighting.
Anopaquesurfacesuchasawallcanalsomakeanexcellentlightsource.Wesimplyneedtoilluminateitwithreflectedlight.Suchanarrangementmayprecludeputtingthedarkbackgrounddirectlyonthewallbecauseitmaygettoomuchlighttophotographasdarkaswewant.
Instead,welikethesetupusedinFigure7.7,whichallowslightingtheopaquereflectivesurfaceasbrightlyaswelikewithoutallowingsignificantlighttofallonthebackgroundthatthecamerasees.Attachingthedarkbackgroundtoalightstandorsuspendingitfromabovewithstringworksfine.
Theresultofbothofthesearrangementsisthesame:adarkbackgroundissurroundedbybrightlight.
Likethelightsource,theexactsizeofthebackgroundisnotcritical.Aswiththebright-fieldapproach,wecanadjusttheeffectivebackgroundsizebythecameradistance.Theonlysizelimitationisthatthedarkbackgroundmustbesmallenoughtoleaveplentyoflightvisiblearoundit.
White
Background
BlackCard-
7.7Thissetupallowsyoutolighttheopaquereflectivesurfacebrightlywithoutlightingthepartofthebackgroundthatthecamerasees.
Glass
Subject
Light
PositiontheCamera
Again,thebackgroundshouldexactlyfillthefieldofviewofthecamera—nomoreandnoless.Thisisimportantforreasonssimilartothoseinthebright-fieldapproach.Ifthedarkbackgroundistoolarge,itwillextendintothefamilyofanglesthatproducesdirectreflection.Thatwouldblocklightneededtobrightlydefinetheedgeoftheglassandtokeepitfromdisappearingintothedarkbackground.
PositiontheSubjectandFocustheCamera
Next,movethesubjectbetweenthecameraandthebackgrounduntilitisthesizewewant.Onceagain,edgedefinitionimprovesasthesubjectmovesclosertothecamera.Finally,focusthecameraonthesubject.Asinthebright-fieldmethod,thechangeinbackgroundsizecausedbyrefocusingwillbetoominimaltocauseproblems.
ShootthePicture
Accurateexposuredeterminationwiththissetuprequirestheuseofaverynarrow-anglespotmetertoreadthehighlightsontheedgesoftheglass.Inmostcompositionsofthissort,“verynarrowangle”means
muchlessthan1degree.Almostnophotographershavesuchameter.Donotdespair.Fortunately,anyconventionalreflectionmeter(includingthoseinmanycameras)cangiveanacceptablycloseapproximationofthedesiredexposurewiththehelpofbracketing.
Toseewhythefollowingmethodworks,wemustrememberthatpuredirectreflectionsfromasubjectareasbrightasthelightsourcethatproducesthem.Thosereflectionsmaybetoosmalltoread,butthelargesourceisnot.
First,placethemetercloseenoughtothelightsourcetoreaditalone.Readtheedgeofthelightsourcebecausethatisthepartilluminatingtheglass.
Next,tophotographtheglassasnearwhite,exposetwostopsmorethanthemeterindicates.(Thisisbecausethemeterthinksitisseeing18%grayinsteadofwhite.)Thisisagoodexposureifthehighlightontheglassisperfectunpolarizeddirectreflection.Suchanexposureistheoreticallyimportantbecauseitdeterminesthestartingpointforthebracket.Inpractice,thereisnopracticalchancethatthedirectreflectionisbothperfectandunpolarized,sowemaywantsimplytonotethisexposureandtomoveontothenextone.Becauseperfectdirectreflectionsrarelyoccur,tryadditionalexposureswithone,two,andthenthreestopsmoreexposure.
Allofthisassumesthebackgroundremainsblackbecauselittleornolightisfallingonit.If,however,
wedesireittobealightervalue,itwillthenbenecessarytouseadditionallightjustforthebackground.Omittingthisadditionallightandattemptingtolightenthebackgroundbyincreasingexposure(accordingtothemeteringprocedurerecommendedinthediscussionofthebright-fieldmethod)willusuallyoverexposethesubject.
Onceagain,wehaveusedanidealexamplethatavoidscomplexitiesforthesakeofsimplicity.Deviatefromthisidealasmuchasthecompositionrequiresbutnomore.
THEBESTOFBOTHWORLDS
Bright-fieldanddark-fieldmethodsareeasytolearn,buttheycanbedifficulttocombine.Mostfailuresinphotographingglassresultfromdeliberatelyornaivelyusingbothsimultaneously.
Forexample,wehaveknownsomephotographerswhotriedtolightglassinatentliketheonedescribedinthepreviouschapter.Theysuccessfullyeliminatedextraneousreflections,buttheyequallysuccessfullyeliminatedtheedgeoftheglass.Thepartofthetentvisibletothecameraprovidedalightbackground.Therestofthetentlittheglass.Theresultwasthelight-on-lightapproach.
7.8Aclassiclightingarrangementinwhichpartofthesceneisbrightfieldandtheotherpartisdarkfield.
Usingthetwomethodstogetherrequiresthatwekeepthemseparate,eveninasinglepicture.Wemakeamentaldivisionofthesceneanddecidethatonepartofthepictureistobebrightfieldwhiletheotheristobedarkfield.WehavedonethisinFigure7.8,inwhichthefrostedwhiteplasticisilluminatedfrombelowbyasmalllight.
Noticethatwehavenottrulycombinedthetwobasicmethods.Partisbrightfieldandpartisdarkfield.Whereverthetwomethodsremaindistinct,theglassiswelldefined.Onlyinthetransitionarea
dothetwomethodsmix.Therecanbeanoticeablelossthere.However,bykeepingthetransitionsmallthisproblemcanbeminimized.
SOMEFINISHINGTOUCHES
Uptothispointwehavediscussedtechniquesthatdefinetheshapeofglassware.Asyouhaveseen,wecandefinethesubjectshapebyusingeitherdarklinesagainstalightbackgroundorbyusinglightlines
againstadarkbackground.Thesetwotechniquesarethefoundationforlightingglass.However,weoftenneedadditionaltechniquestoproduceasatisfactoryphotograph.Intheremainderofthischapter,wewilldiscusssomefinishingtouches.Specifically,wewillexaminehowtoaccomplishthefollowing:
1.Definethesurfaceofglassware.
2.Illuminatethebackground.
3.Minimizethehorizon.
4.Stopflare.
5.Eliminateextraneousreflections.
Becausethesetechniquesareprimarilyusefulindark-fieldsituations,wewilldemonstratethemusingthatapproach.
DefiningtheSurfaceofGlassware
Inmanysituations,itisnotenoughmerelytodefinetheedgesofasubject.Itisnotenoughjusttoshowitsshape,nomatterhowbeautifullywedoit.Frequently,thephotographmustalsoclearlyshowtheglasssurface.Toaccomplishthis,wemustcarefullymanagethehighlightsthatreflectfromthesurfaceofthesubject.
Largehighlightsareessentialtoglasssurfacedefinition.Toseeproofofthis,comparethehighlightsonFigure7.9withthoseseenearlierinFigure7.1.
ThetinybrightspotsinFigure7.1areharshlydistractingattheleastandmeaninglessatbest.TheoppositeistrueinFigure7.9.Insteadofcompeting,thelargerhighlightsprovidetheviewerwithinformation.Ratherthanclutteringtheotherelementsofthephotographfortheattentionoftheviewer,itservestheconstructivepurposeofsaying,“Thisishowthisglasssurfacelooksandfeels.”
Definingaglasssurfacerequiresahighlightoftherightsizeintherightplaceonthesurfaceofthesubject.Fortunately,thatisnottoodifficult.Doingitsuccessfullysimplyrequiresrememberingwhatthetheoryofreflectiontellsusabouthowdirectreflectionbehaves.
Wehaveseenthatalmostallreflectionsfromaglasssurfacearedirectreflectionsandthatdirectreflectionsalwaysobeystrictrulesthatpredicttheanglesatwhichtheyoccur.Now,lookatFigure7.10.
Assumingwewanttocreateahighlightontheareashownontheglasssurface,weneedtofilltheindicatedfamilyofangleswithlight.Theseareallofthedirectionsandtheonlydirectionsfromwhichlightcanproducedirectreflectiononthatpartoftheglass.
Noticethattheroundedglasscausesthissmallsubjecttoreflectmuchofthestudioinitssurface.Forthisreason,lightingforsurfacedefinitioncansometimesrequiresurprisinglylargelightsources.
7.9Largehighlightsaddsurfacedefinitiontotheglasswareinthispicture.
Figure7.10showstwopossiblewaystoprovidesuchalightsource.Lightsourcesateitherofthetwopositionswouldlighttheglassequallywell.However,oneneedstobeseveraltimesthesizeoftheotherifitistocovertherequiredfamilyofangles.
Determiningthedistancebetweenthephotographiclightandthediffusionsheetcanbeanimportantdecision.Noticethatinthefirstphotographinthisseries,thelightwascloseenoughtolightbrightlyonlythecenterofthediffusionmaterial.Figure7.11showsan
Glass
Subject
aVi*e
PossibleDiffusionSheetPositions
¥<\
\c*
¥’Pr¥
Light
7.10Creatingahighlightontheindicatedsurfacerequiresfillingitsfamilyofangleswithlight.Inthisdiagram,alighteddiffusionsheetreflectsontheglasssurfacetoproducethehighlight.
alternativemethod.Herewehavepulledthelightheadfartherback.Thisallowsthefullrectangleofthediffusionsheettobelitandtobereflectedintheglasssurface.
Lightingthewholediffusionsheetmoreevenlyproducesalargerhighlight,butweusuallywanttokeepthatlargerhighlightdimmer.Hadwelitthewholediffusionsheetbrightly,itwouldhavereflectedintheglassasanobvioushard-edgedrectangle.Thisreflectionwouldhaveadvertisedthepresenceofastudiolightanddetractedfromtherealityofthescene.
Regardlessofwhereweputthelight,wesometimesminimizethestudiolookwithstripsofblacktapeonthediffusionsheet.Then
7.11ComparethelargehighlightinthispicturewiththatinFigure7.9.Thistimewepositionedthelightfarenoughawayfromthediffusionsheetthattheentiresheetwaslitandreflectedintheglass.
thereflectionofthelightappearstobethatofawindow,asshowninFigure7.12.
Beforewemoveon,noticethatthesearethefirstexamplesinthischapterinwhichthelightdoesnotcomefrombehindtheglass.Thisenablesustobetterdefineglassthatdoesnothaveasimple,smoothsurface.Itisalsousefulwhenthereareadditionalnontransparentsubjectsinthescene.Laterinthischapterwewillseemoreexamplesofthistechnique.
7.12Weusedtapetoreducethe“studiolook”ofthisshotandtogivetheillusionofawindowbeingreflectedontheglasssurface.
IlluminatingtheBackground
Thebasicdark-fieldapproachproducesapictureinwhichthebackgroundappearsdarkregardlessoftheactualtoneofthebackgroundmaterial.Brighteningthatbackgroundmaterialrequiresanadditionallightsource.
Tobrightenadark-fieldbackground,wesimplyputanadditionallightonthedarkbackground.Wepositionthislightsimilarlytoone
usedtoproducebright-fieldilluminationonawhiteopaquebackground.Usually,wecanevenusealightofsimilarintensitybecausethedarkerbackgroundmaterialwillkeeptheresultfrombecomingabright-fieldphotograph.
Figure7.13wasmadethisway.Noticethatthetoneofthebackgroundhasbeenlightenedtoamediumgrayandthattheglassisfreefromanyextraneousreflections.
7.13Alightonthebackgroundsignificantlybrightenedareasofthebackgroundinthisdark-fieldshot.
MinimizingtheHorizon
Glassthingshavetobeputontables;tablescausehorizonlinesinphotographs.Whatcanwedoifwedecidethatthehorizonisanundesirabledistraction?
Eliminatingthehorizoniseasierinphotographsofsubjectsotherthanglass.Nonglassphotographicsubjectsallowustousealargeenoughtabletokeepthetableedgeoutoftheimagearea.Alternatively,wecanuseasweepofseamlesspaper,raisingitstopedgehighenoughtopreventthecamerafromseeingit.Thesemethodswillworkforglasssubjectstoo,butnotaswell.
Rememberthatthebestlightingoftheglassrequiresabackgroundthatbarelyfillstheimagearea.Largetablesandpapersurfacesinterferewiththisrequirement.Ifthebackgroundislight,wecancoverwhateverpartdoesn'tshowinthescenewithanythingdark.Thisproducesreasonablygoodbright-fieldillumination.
Wecanalsousewhiteorsilverreflectorstocoverpartofadarktablefordark-fieldillumination.This
tendstobesomewhatlesseffectivebecausethelightonthereflectorsisthesamesourceilluminatingthetable.Therightamountoflightonthereflectorsmaybetoomuchforthetable.Therefore,ifthetableisnotanessentialelementinthecomposition,wewouldprefertogetridofitaltogether.Wecannotdothat,butthereareseveralwaystoapproximatetheeffect.
Atransparentglassoracrylictablesurfaceresemblesanonexistenttablemorecloselythananythingelse.Inmostprecedingphotographs,weusedatransparenttable.Thebackgroundwasvisiblethroughthetable,sothedistractinghorizonlinewasminimized.Thetransparencyofthetableallowedthebackgroundlighttopassthroughandilluminatethesceneasifthetabledidnotexist.Figure7.14showslightcriticaltodefiningthisglass,whichcouldpassthroughatransparenttablebutwouldbeblockedbyanopaqueone.
Anotherreasonableapproachistoplacethesubjectonamirror.Thereflectionofthebackgroundinthemirrorshowslessabrupttonaldifferencebetweenthebackgroundandtheforegroundthanotheropaquesurfaces.Evenbetter,reflectionfromthemirrorsurfacecanlightglasssurfacesalmostaswellaslightpassingthroughatransparenttable.Thehorizonislikelytobevisiblebutlessobtrusive.Aninterestingvariationonbothoftheseapproachesistomisttheglasstablewithwater,thusdisruptingandcamouflaginganypotentiallydisturbingreflectionsofthesubject.
However,evenatransparenttableoramirrorcanproduceaslighthorizonline,andtherearesituationswhenreducingthevisibilityofthehorizonisnotgoodenough.Somepicturesrequirethatthehorizonbe
Diffusion
Material
Black
Card
Glass
Subject
Blocked
Light
Light
7.14Atransparenttableallowslighttopassthroughasifthetabledidn’texist,butanopaquetableblockslightessentialforedgedefinition.
eliminatedaltogether.Intheseinstances,wecanuseapaperwedgeliketheoneshowninFigure7.15.
Inthisexample,thepaperwedgeistapeddirectlytoalargesheetofdiffusionmaterial.Alightbehind
thediffusionmaterialprovidesillumination.Ifwecutthepaperwedgecarefullysothatitfitsthefieldofviewofthecameraexactly,therewillbenosacrificeofthelightingquality.Figure7.16showstheresultofsuchanarrangement.
StoppingFlare
Thebasicdark-fieldapproachtophotographingglasswareisprobablytheworstflare-producingarrangementthatwecouldencounter.
7.15Apaperwedgesuchasthisonewilleliminatethehorizonbutmaintainedgedefinition.
Wehavediscussedtheprinciplesofcameraflareinearlierchapters.
Dark-fieldlightingexaggeratestheproblembygivingcameraflaretheopportunitytooccuronallfoursidesoftheimage.Figure7.17isanextremeexample.
Eveniftheflareisnotbadenoughtoproduceavisiblefoggingoftheedgeoftheimage,thegeneraldegradationoftheimagefromallsidesaccumulates.Atbest,wegetapicturewithlowcontrast.
Fortunately,thisproblemiseasytocorrectifweunderstandandanticipateit.Weusegobosjustaswedidearlierinthisbook,butwehavetoremembertoblockthenonimaginglightstrikingthelensfromallfoursidesofthefieldofview.
Wemakesuchagobooffourcardboardbladesorofasingleboardwitharectangularhole.Thenweclampittoalightstandinfrontofthe
7.16AphotographmadeusingthepaperwedgeillustratedinFigure7.15.Theedgedefinitionisgoodonalmostallpartsoftheglass,andthereisnohorizon.
EliminatingExtraneousReflections
Becauseglassreflectsinamirror-likemanner,anythingintheroommayreflectinthesubject.Therefore,aftersatisfactorilylightingapieceofglassware,wemustfinishthejobbyremovinganyextraneousreflectionscausedwhileputtingtogetherthesetup.Thisisespecially
7.17Becausecameraflarecanoccuronallfoursidesoftheimage,itisessentialtousegobostopreventitwhenusingdark-fieldlighting.
trueofdark-fieldlightingbecausethedarkbackgroundvisiblethroughtheglassmakesthebrighterextraneousreflectionsparticularlyvisible.
Thefirststepingettingridoftheseunwantedreflectionsistofindwhichobjectsinthesurroundingareaarebeingmirroredintheglasssurface.Oncewehavedonethis,therearethreebasicstrategiesfromwhichtochoose.Oftenweuseacombinationofthesestrategies:
1.Eliminateobjectsthatcreateoffendingreflections.Theeasiestwaytodealwithhighlyreflectiveobjectssuchasextralightstandsandunusedreflectorcardsissimplytogetthemoutoftheroom.
7.18Lightingthediffusionsheetcanalsolightthecamera,causingareflectionofthecamerainthesubject.Inthissetupwehaveusedablackcardasagobotopreventtheproblem.
2.Blockthelightfallingontheoffendingobjects.NoticethatinFigure7.18,thelightthatissupposedtolightthediffusionsheetnexttothecameraisalsofallingonthecameraitself.Agobobetweenthelight
onthecameradarkensthereflectionofthecamerasufficientlythatitisnolongervisibleinthesurfaceoftheglass.
3.Darkentheobject.Finally,ifthelightcannotbeblockedfromtheoffendingobject,wemaybeabletosufficientlydarkentheobjectbycoveringitwithblackcardsorcloth.
COMPLICATIONSFROMNONGLASSSUBJECTS
Theinformationthatwehavepresentedsofarinthischapterisallweneedtolightglasssubjects.However,inmanycasesweneedtoincludenonglassobjectsinthesamepicture.Thebestlightingfortheglassmaybetheworstlightingfortherestofthescene.
Asexamples,wewilllookatthetwosubjectsmostlikelytoaccompanyglass:aliquidinaglassandalabelonabottle.Theremediesweproposewillbeusefulforothersubjectsaswell.
LiquidsinGlass
Weareoftencalledontophotographglasswarefilledwithliquid.Bottlesfullofbeer,glassesfullofwine,vialsfullofperfume,andbowlsfulloffishallproduceaninterestingchallenge.
LiquidasaLens
Opticallawsdictatethataround,transparentcontainerfilledwithaliquidis,infact,alens.Thetroublesomeresultofthisisthataliquid-filledsubjectmayrevealsurroundingsthatwewouldprefertheviewernotsee.
Figure7.19isagoodexampleofwhatcanhappen.Itwasmadefromthesame“normal”viewpointusedearlierfortheglasswithoutliquid.
7.19Noticehowthe“liquidlens”inthiswineglassrevealstheedgeofthebackgroundanddarkenstheapparentcoloroftheliquid.
Weseethatabackgroundlargeenoughtofillthefieldofviewofthecameraisnotlargeenoughtofillthefieldofview
thatisseenthroughtheliquid.Thewhiterectangleinthecenteroftheglassisthebackground.Thedarkareaarounditis
therestofthestudio.
Ourfirstinclinationmightbetousealargerbackground(ortoincreasetheeffectivesizeofthebackgroundbymovingit
closer).However,wehaveseenthatusingabackgroundlargerthanthefieldofviewsacrificesthebestdelineationofthe
glass.Suchasolutionissometimespractical—butnotinachapterdevotedspecificallytowell-definedglass!Forthe
presentneed,wewillhavetothinkofanothertechnique.
Thesolutiontothisproblemrequiressimplymovingthecameraclosertothesubject.Then,ifnecessary,substitutea
shorterfocal-lengthlenstoobtainasimilarimagesize.Thisenablestheexistingbackgroundtofilltheareaseenthrough
theliquid.
Remember,however,thatacloserviewpointalwaysincreasesperspectivedistortion.Theincreaseddistortionisapparent
inthedeeperellipseoftherimoftheglass,asshowninFigure7.20.Mostpeoplewouldnotconsiderthisadefectinthis
particularphotograph,butthedistortioncouldbeoffensiveinanotherscenewithotherimportantsubjectsorfromahigher
orlowerviewpoint.
KeepingTrueColor
Supposeaclientneedsapictureofaglassoflightbeerinfrontofadarkbackground.Aliquidinatransparentcontainer
alwaystakesonthecolorofitsbackground.Ifwearenotcareful,wewillturnthelightbeerintoadarkone!Theproblem
isshowninFigure7.21.
Thesolutiontothisproblemistosetupasecondarywhiteorsilverbackgroundjustbehindtheglass.Thissecondary
backgroundmustbethesameshapeasthesubject,eveniftheglassisstemmedorhasanirregularshape.Thesecondary
backgroundmustalsobelargeenoughtofillasmuchoftheareabehindtheliquidaspossible,withoutextendingfar
enoughtobevisiblebeyondtheedgesoftheglass.Allthissoundstedious,butinpracticeitisnot.Figure7.22showsone
easywaytoconstructthesetup.Herearethesteps:
1.Placeawhiteorsilvercardbehindthesubject.Somephotographerspreferafoilwithacolorsimilartotheliquid,
suchasgoldforbeer.Aflexiblewiretapedtothetablesurfacecanmakeaninvisiblesupportforthecard,butdonot
attachthecardfirmlyyet.
2.Removethecamera,andreplaceitwithatestlightaimedatthesubject.Thiswillcastashadowofthesubjectonthe
materialfromwhichwecutthebackground.
7.20Movingthecameraclosertothesubjectallowedthebackgroundtofilltheentireareaseenthroughtheliquid-filledglass.
3.Outlinetheshadowofthesubjectonthebackground.Afelt-tipmarkerishandyforthis.Afteroutliningtheshadow,
removethecardandcutitout.
4.Repositionthecutoutbehindthesubject.Atthispoint,wecanalsoremovethetestlightandreplaceitwiththe
camera.Lookat
7.21Inthisshot,adarkbackgroundhasturnedalightbeerintoadarkone.
7.22Onesetupthatusesasecondarybackgroundwithalight,neutraltone.
LightforSecondaryBackground
Turnedoffwhilemakingtracing
TestLight
Temporarily
Replaces
Camera
Q
ShadowCastbyTestLight
SecondaryBackground
7.23Thebeerhastherightcolorthistime,thankstoalight-coloredsecondarybackground.
thesubjectthroughthecameraandmakesurethatthecardandthecameraareaccuratelypositionedandthattheedgesof
thecardcannotbeseen.
5.Placeanadditionallightsothatitilluminatesonlythecutout.Usebarndoorstokeepthelightoffthelensandthe
subject.Figure7.23showstheresult.
SecondaryOpaqueSubjects
Aliquidislikelytobetheonlytransparentsecondarysubjectinaphotographofglass.Othersecondarysubjectsaremore
oftenopaqueand,therefore,morelikelytoneedlightingtechniquesbeyondthoseadequateforthetransparentglass.
TheusuallightingforsuchascenebeginswiththelightingarrangementusedearlierinFigure7.10.Thesamelightthat
producesa
highlightonthefrontsurfaceoftheglasscanalsogivegoodilluminationforanopaquesecondarysubject.Inmanycases,
thisisenough.Thenextstepistomaketheexposure.
Unfortunately,othersubjectsrequiremorework.Apaperlabelisoneofthemostcommonexamples.Rememberthatwe
seeneitherperfectdirectnorperfectdiffusereflectioninnature.Althoughmostofthereflectionproducedbymostpaperis
diffusereflection,someofitisdirect.Thelightingthatproducesdirectreflectionontheglasssurfaceisalsolikelyto
obscurethepaperlabel.Figure7.24isanextremeexample.
Thisparticularcamerapositionallowstworemediestothisproblem.Oneistomovetheoffendinglighthigher;thenany
directreflectionfromthepapergoesdownwardinsteadoftowardthelens.
7.24Thesamelightingthatproducesdirectreflectiononglasscanalsocauseitonapaperlabel.Theresultisreducedlegibility.
Ifgoodhighlightplacementontheglasspreventsyoufrommovingthelight,useasmallopaquecardtoblockthelight
fromjustthoseanglesthatproducedirectreflectionsonthelabel.Thepositionandsizeofthisgoboarecritical.Ifit
extendsbeyondthefamilyofanglesdefinedbythelabel,itwillreflectintheglass.Weseetheresultingphotographin
Figure7.25.
Changingthepositionofthelightoraddingagobowillalmostalwaysremovethedirectreflectionfromasecondary
subjectwithoutharmingthelightingoftheglass.
Wemayalsoconsiderapolarizingfilterasathirdremedy.However,thissolutionisrarelyeffectivebecausemuchofthe
desirablehighlightontheglassisusuallyalreadypolarized.Ifthepolarizereliminatestheoffendingreflectionfroma
label,itisalsolikelytointerferewiththelighttheglassneeds.
7.25Hereweseetheresultofusingagobotoblocklightfromthoseanglesthatproducedthedirectreflectionsonthelabelinthispicture.
RECOGNIZINGTHEPRINCIPALSUBJECT
Inthischapterwehavetalkedaboutusingbright-fieldanddark-fieldmethodsforlightingglass.Wehavealsodiscussed
someremediestomanagecomplicationscausedbycompetingnonglasssubjects.However,wehavenotsaidverymuch
aboutwhentousewhichofthesetechniques.
Thenatureofthesubjectdeterminesthebestlighting.Decidingwhichsubjectismoreimportantisthefirststepinlighting
ascenethatincludesbothglassandnonglass.Shouldwelighttheglassaswellaspossibleandthenmakeadjustmentsto
accommodatetherestofthecomposition?Shouldwefirstestablishthegenerallighting,andthenaddanysecondary
lights,reflectors,orgobosneededtoenhancetheglassabit?
Wecannotmaketheseeditorialandartisticdecisionsonapurelytechnicalbasis.Wemightlighttwoidenticalscenes
differently,dependingonwhatistheintendedpicturecaption,onwhoispayingourbill,oronpersonalwhim.
Seeinghowlightbehavesmattersmorethanthemereabilitytomakearoutineglasswareshotlookprofessional.We
devoteawholechaptertolightingglassbecausegenerationsofphotographershavefoundglasstobeaclassicsubjectthat
teachesustosee.
8
AnArsenalofLights
Goodlightingisoneofthemostimportantaspectsofportraitmaking.Wecandoeverythingelsebeautifully,butifour
lightingispoorourpicturewillsuffer—oftenfatally.Itisthatsimple.Andwiththatinmind,wewilllookatsomeofthe
factorsthatitisimportanttokeepinmindwhenlightinganyportrait.
Wewillstartbyexplainingthesimplestofallportraitlighting;theuseofasinglelightsource.Wecallthelightthat
providesmostoftheilluminationforanyportraitthemainorkeylight,andwegenerallyhandlethislightthesameway.
Thisistruewhetherweuseitaloneorwithadditionallights.
Asidefromthemainlight,thischapteralsointroducesmorecomplexlightingarrangementsthananywehavediscussed
earlier.Suchso-calledclassicportraitlightingrequiresseverallights.Mostoftheselightscouldservesimilarneedsfor
anysubject.Ifyoudecidenottouseallofthemforportraiture,youprobablywillusethemforsomethingelselater.
Therefore,wesaymoreaboutthefilllightthanwehavebefore.Fromtherewewillmoveontoexplaintheuseofother
lights,suchaskickersandhairlights.
THESINGLE-LIGHTSETUP
Simple,yes.Simplistic,no.Asinglelightisadequateformostportraits;therestareoptional.However,evenonelight
needstobeusedwell.Otherwise,noamountofadditionallightingwillsalvagethepicture.
TheBasicSetup
Figure8.1isadiagramofthesimplestpossiblesetup.Initasinglebarebulbthathasbeenplacedtoonesidelightsthe
subject.Sheissitting
8.1Hereisadiagramofthesimplestofstudioportraitlighting.Thesubjectislitbyasinglebarebulbthatisplacedtooneside.
severalfeetinfrontoftheplainbrownwallthatservesasabackdrop.Thispositioningisimportant.Weresheclosertothe
wall,herbodywouldcastapotentiallydistractingshadowonit.
Figure8.2isaportraitmadewiththelightingsetupwehavejustdescribed.Insomeways,itisasatisfactorypicture.Itis
sharp,properlyexposed,andacceptablycomposed.However,itsuffersfromoneveryseriousfault:harsh,distracting,and
veryuncomplimentaryshadows.
NowlookatFigure8.3.Itshowsthesameyoungladyinthesamebasicpose.Thistimetheimagewasmadewithasingle
bulbinsideasoftboxinthesameplaceasbefore.
Butlookatthedifferencebetweenthepictures.Thehard-edged,unattractiveshadowsthatproducedsuchanunpleasant
picturebeforehavevanished.Thesoftershadowsofthislightinghelp,ratherthandetractfrom,thepicture.Theyhelp
definethefeaturesandaddanelementofdepthandinteresttothepicture.Theresultismorelikelytopleasemostpeople,
especiallythesubject!
8.2TheresultofthelightingdiagrammedinFigure8.1.Theharsh,uncomplimentaryshadowsintheportraitdistractfromthefeatures.
8.3Thesoftershadowsinthispicturearetheresultofalargerlightsource.Theseshadowsdefinethefeaturesofthesubjectandadddepth.
Intheoryanylightworks,butthetheoryislesspracticalforportraiture.Whensubjectsdon’tmoveandwecanspendawholedayonasingleshot,it
makeslessdifferencewhattypeoflightingequipmentweuse.Butportraitsubjectsdon’twanttowaitseveralminuteswhilethephotographer
movesa4-by-8-footdiffusionsupportedbytwolightstandsplusalight.There’snothingwrongwithbeginnerphotographersusingimprovised
equipment,andwe’vedonesoinafewpicturesinthisbooktoproveitcouldbedone.
Professionalportraitphotographersdon’thavetimeforthis,however,so,inalmostallcases,theirprincipallightsaresoftboxes,umbrellas,ora
combinationofthetwo.Theseallowfairlylargelightstobequicklypositionedandadjusted.Theclothdevicescanalsobequicklycollapsedor
foldedtoasizeconvenienttocarrytoanotherlocation.
Furthermore,forprofessionalportraitphotographers,thelightinsideofthosedevicesisalmostalwaysstudiostrobe(evenawayfromthestudio).
Theseflashin1/250to1/1000ofasecond,tooquicklyformostpeopletoblink.Betweenflashestheyemitalightbrightenoughforthe
photographertoseewhatthelightisdoingbuttoodimtocausesquintingorpupilconstriction.
LightSize
Andjustwhatisitthatmadesuchadifferencebetweenthetwoportraitswehavejustseen?Whyweretheshadowshard
andunpleasantinoneandsoftandflatteringintheother?Theanswerissimpleandfamiliar:lightsize.Thefirstportrait
wasmadewithasinglesmall,barebulb.
Aswehaveseen,suchsmallsourcesoflightproducehard,sharplydefinedshadows.Thesecondpicturewasmadewitha
largelightsource.Theresultsprovetheprinciplethatlargelightsourcesproducesoftshadows.
Inthisparticularexample,weenlargedthelightsizeintheeasiestmannerpossible.Weputatranslucentlampshadeover
thebulb.Thisincreaseditseffectivesize10-fold.
Thelampshadewasaquickandeasysolutiontotheproblemofhardshadows,butitwasfarfromtheonlyoneavailableto
us.Forexample,wealsocouldhaveincreasedtheeffectivesizeofourlightsourcebyhangingasheetoftracingpaperor
plasticdiffusionmaterialbetweenthelightandthesubject.Itisworthnotingthatwecouldhaveaccomplishedthesame
goalbybouncingalightfromanumbrella.Theseapproachesalldothesamething.Theymakethelightsizelargerand
thustheshadowssofter.
SkinTexture
Thesizeofthelightsalsoinfluencestheamountoftexturewecanseeintheskin.Skintextureappearsasmicroscopic
shadowsinthephotograph.Suchshadowsmaybeeitherhardorsoft,justastheshadowsof
B
8.4Comparetheskintextureintheseenlargements.PictureAwasmadewithasmalllight.Noticehowpronouncedtheskintextureis.PictureBwasmadewithasoftlightandlookssmoother.
A
thegeneralfeaturesmaybe.WecanseethisclearlyintheenlargementsinFigure8.4.
Thisdifferenceintexturemaynotmatteriftheimageisreproducedatasmallsizeinabookormagazine,especiallyifthe
subjectisyoung.However,peopleoftenhangverylargeportraitsonthewall.(Mostphotographerswhodoconsumer
portraitureusuallytrytosellprintsaslargeaspossibletoincreasetheirincome.)Ageandweatheraddenoughskintexture
tobevisibleinevensmallpicturesofmanypeople.
WheretoPuttheMainLight
Placingthemainlightis,ofcourse,ourfirstdecision.LookattheabstractballinFigure8.5.Itisthesimplestthingwe
coulddrawtoconvincinglyrepresentaball;withoutthehighlightandshadow,itcould
8.5Theplacementofthehighlight,aboveandtotheleftorrightofcenter,simplyfeelsnatural.
justaswellbearing,ahole,oradisk.Noticealsothattheplacementofthehighlightsimplyfeelsmore“right”thanifwe
hadcenteredit,say,orputitnearthebottomofthesphere.
Themostcommonplacementoftheportraitmainlightisaboutwherewehaveitinthesphereillustration.Facesaremore
complex.Theyhavenoses,eyesockets,mouths,wrinkles,creases,andalltheotherirregularitiesthatcomeaspartofthe
humanform.Let’slookatalloftheseaswefine-tunethebasiclightplacement.
Generallyspeaking,weprefertopositionthelightsothatthereisashadowononesideoftheface.This,aswehaveseen,
isaccomplishedbykeepingthelighttooneside.Inaddition,wewanttokeepithighenoughsothattherearesimilar
shadowsundertheeyebrows,nose,andchin.Havingreadthis,however,youmaywellaskjusthowfartokeepthelight
“tooneside”andhowhighis“highenough.”Thesearevalidquestions.Webegintoanswerthemwithalookatavery
usefulhelper—thekeytriangle.
TheKeyTriangle
Theproperplacementofthistriangularhighlightisthebasisofmuchgoodportraitlighting.Usingthekeytriangleasa
guidetogoodlightingissimplicityitself.
Allwehavetodoismovethelightarounduntilweseeatriangularshapedhighlightonoursubject’sfaceliketheone
showninFigure8.6.Thebaseofthekeytriangleshouldrunthroughtheeye,anditspointshouldextenddownthecheek
approximatelytothelipline.
8.6Thekeytriangleextendingfromtheeye,throughthecheek,totheliplineisthestartingpointforgoodclassicportraitlighting.
Theimportanceofthekeytriangleisitsabilitytoletusseelightingdefectsbeforeshooting.Someofthesubtletiesof
goodlightingbecomeeasytoseewhenwelookattheboundariesofwherethekeytrianglefalls.
Wewilllookatthethreemostcommonvariationsandseewhatmightbewrongwiththem.Noneofthesepotential
“defects”isaninevitablyfatalsinineverypicture;everyoneofthemhasbeenusedatonetimeoranothertomakeagood
portrait.Theyare,however,deviationsfrom“standard”portraitlighting,whichweshouldnotcommitinanypicturewe
intendtosellorsubmitforagradeuntilfullymasteringthebasics.
KeyTriangleTooLarge:MainLightTooNeartheCamera
AsFigure8.7shows,placingthelighttoonearthecameraandinfrontofoursubjectlightshertoouniformlytoshow
goodcontourinherface.(Theextremeexampleofsuch“flat”lightingcomesfrommountingastrobedirectlyontopof
thecamera.)
8.7Flatlightingshowslessoffacialcontoursthansidelighting.Itresultsfromplacingthemainlightnearthecameraandinfrontofthesubject.
Evaluatingwhetherthelightingistooflatcanbedifficultforphotographerswhoarejustbeginningtolearnportrait
lighting,especiallyifthepicturewillbeprintedinonlyblackink.Anticipatinghowcolortranslatestoshadesofgraytakes
practice.Butthedecisionbecomessimplewhenweseethatsuchlightingalsomakesthekeytrianglesolargethatitisno
longeratriangle.
Wecanusuallyimprovesuchlightingbymovingthelightfarthertothesideandhighertoreducethesizeofthekey
triangle.Tomaximizecontour,wemovethelightfarenoughtogetthekeytriangleassmallaspossiblebutstopjustshort
ofcreatingeitherofthefollowingtwoproblems.
KeyTriangleTooLow:MainLightTooHigh
Regardlessofwhethertheeyesareawindowtothesoul,theyarecertainlyessentialtoalmostanyportrait.Keepingthe
eyesofthesubjectinshadowcanbeunsettlingtoanyonelookingattheportrait.
Figure8.8illustratesthisproblem.Noticehowthestrongeyeshadoweliminatesthetopofthekeytriangleandproduces
anunnatural
8.8Theunsettling“raccooneyes”thatweseeherecomefromliftingthemainlighttoohighabovethemodel’sface.
andghoulishpicture.Thisshadowistherebecausewepositionedourlighttoohighabovetheheadofthesubject.Fixing
theproblemsimplymeansloweringthelightabit.
KeyTriangleTooNarrow:MainLightTooFartoSide
Figure8.9illustratesstillanotherpotentialproblem.Wepositionedthelightsothatthenosecastsadarkshadowacross
hercheek.Thisshadowblocksthekeytriangle.
Oncemorethecureissimple.Toavoidashadowsuchasthisone,allwehavetodoismovethelightabitmoretothe
front.Whenwedothis,thekeytrianglewillreappear.
LeftSide?RightSide?
Photographersgenerallyprefertoputthemainlightonthesamesideasthesubject’sdominanteye,ortheeyethatappears
tobemoreopenthantheother.Thegreaterthevisibledominanceoftheeye,themoreimportantitisthatwelightthat
side.Ofcourse,somepeoplehavevery
8.9Theresultofpositioningthemainlighttoofartooneside.Themodel’snosecastsashadowacrosshercheek,blockingthekeyhighlight.
symmetricalfeatures;thenitmakesnodifferenceonwhichsideweputthemainlight.
Theotherinfluenceonourdecisioniswheretheperson'shairisparted.Lightingonthesamesideasthepartprevents
extraneousshadows,especiallyifthehairislong.
Somepeopleabsolutelyinsistthatwephotographthemfromonesideortheother.Oftenweshouldlistentosuchopinions
becausetheyarebasedonthatindividual'sdominanteyeorhairstyle,whetherthepersonknowsitornot.Justbesurethat
thesubjecthasnotconfusedthe“good”sidewiththe“bad”sidewhenlookinginamirror!
BroadLightingorShortLighting
Sofarwehavemadeallpictureswiththemodelapproximatelyfacingthecamera.Whetherthelightwasontherightor
theleftwouldhavemadeonlyaminordifference.However,thedifferenceismajorifthesubjectturnshisorherheadto
eitherside.Wheredowemainlightthen?Figures8.10and8.11showtheoptions.Weeitherputthelightonthesameside
asthesubject'svisibleearorontheotherside.
8.10Puttingthemainlightonthesideoppositethevisible(wereitnotcoveredbyherhair)earproducesshortlighting.
8.11Broadlightingmeansputtingthemainlightonthesamesideasthevisibleear.
Amainlightonthesamesideasthevisibleeariscalledbroadlighting.Positioningthemainlightonthesideopposite
fromyoursubject’svisibleearproducesshortlighting.(Whetherthehaircoversthe“visible”earhasnothingtodowith
whichsideofthefacewearetalkingabout.)
IfyoulookatFigures8.10and8.11again,thereasonbehindthesetwosomewhatconfusingnamesbecomesapparent.
First,lookatthepicturethatwemadewithbroadlighting.Noticethatabroad,orwide,highlightrunsfromthebackofthe
model'shair,acrosshercheek,allthewaytothebridgeofhernose.Now,lookattheportraitthatwemadewithshort
lighting.Thistimethehighlightisquiteshort,ornarrow.Thebrightestpartofitonlyextendsfromthesideofthemodel's
cheektohernose.
Therearenofirmrulesdictatingwhentousebroadandwhentouseshortlighting.Ourpersonalpreference,however,
leansdecidedlytoshortlighting.Itputsthelightwhereitwilldothemostgood,onthefrontoftheface.This,wefeel,
producesbyfarthemostinterestingportraits.
Otherphotographershaveacompletelydifferentbias.Theyfeelstronglythattheshortorbroadlightdecisionshouldbe
basedonthesubject'sbodybuild.Theyprefertouseshortlightingiftheirsubjecthasabroadface.Suchlighting,they
argue,helpsmakethesubjectlookthinnerbyputtingmuchofthefaceinshadow.If,however,thesubjectisverythin,
theylikethewaythatbroadlightingincreasestheamountoftheimagethatishighlightedandmakesthesubjectappear
moresubstantial.
Eyeglasses
Eyeglassessometimesdictatethepositionofthemainlight,regardlessoftheotherpreferencesofthephotographer.Figure
8.12wasshotwithshortlighting.Lookattheresultingdirectreflectionfromtheglasses.
Itisimpossibletoeliminatetheglarewiththelightpositionedasitwasforthisportrait.Wecould,ofcourse,raiseit,but
dependingonthesizeandshapeoftheglasses,bythetimewegetithighenoughitmightfilltheeyewithshadow.
Figure8.13showstheonlysolutionthatalwaysworks.Itisthesamesubjectshotwithbroadlighting.Changingfrom
shorttobroadlightingpositionsthemainlightoutsidethefamilyofanglesthatproducesdirectreflection.
Problemswitheyeglassesincreasewiththediameteroftheeyeglasslenses.Fromanyparticularcameraposition,the
familyofanglesthatproducesdirectreflectionisgreateriftheglasseshavebiglenses.Ifthesubjecthassmalleyeglass
lenses,wecansometimeskeepashortlightingarrangementbyusingasmallermainlight.Itiseasiertopositionthe
smallerlightsothatnopartofthelightiswithinthatfamilyofangles.
8.12Shortlightingproducesanobjectionableglareontheeyeglasses.
8.13Broadlightingeliminatestheglareproblem.
Stilllifephotographersexploringportraiturearesometimestemptedtousepolarizingfiltersonthemainlightandonthe
cameralenstoeliminatereflectionfromglasses.However,thiscancauseotherproblems.Humanskinalsoproducesa
smallamountofdirectreflection.Consequently,eliminatingalldirectreflectioninthehighlightsofaportraitmaygivethe
skinalifelessappearance.
ADDITIONALLIGHTS
Uptothispoint,wehaveshownsomeofthedifferentwaystopositionandmanipulatehighlightsandshadowsusinga
singlelightsource.Thesetechniquesarepowerfulbecausetheyproducefineworkevenifwehaveonlyonelightatour
disposal.
Dependingontaste,wemaybesatisfiedwiththeresultsofasinglelightandproceednofurtherwiththelighting,evenif
wehaveawholestudiofullofstrobesavailable.Thisshouldbereassuringtoanyonenotearningaprofessionalincome
fromphotographyandonlyabletoaffordtolightaportraitwithsunlight.
Still,veryfewphotographersshootingprofessionalportraitsuseasinglelight,sothisbookwilldiscusswhatthoseother
lightsareandhowtousethem.
FillLights
Shadowsareessentialtothesuccessofmostportraits.Muchofthetime,however,weprefertolightenashadoworeven
eliminateitaltogether.Wecandothiswithasinglelightsourceonlyifweplaceitnearthecameralens.Ifwewantto
keepthemainlightfartherfromthecamera,however,weneedsomekindoffilllight.
Photographerscommonlyuseafilllightthatgivesthesubjectabouthalfasmuchilluminationasthemainlight,butthis
guidelineisbynomeansabsolute.Somephotographersliketousealotoffillinportraits,whereasotherequallytalented
onesprefertousenone.Theimportantthingisnottotrytomemorizeanysetofrules;instead,adjustyourlightinguntilit
issatisfactorytoyou.
Somephotographersuseadditionallightsforfill,whereasotherspreferflatreflectingsurfaces.Bothmethodshavetheir
advantages.Themostbasicmultiplelightarrangementconsistsofamainlightplusafilllight.Anadditionallightallows
goodflexibilityinfilllightplacement.Wecanputthefilllightfarenoughfromthesubjecttobeoutofthewayandstill
expectittobebrightenough.
Figure8.14wasmadewithasinglefilllight.Weturnedoffthemainlightsothatyoucouldseeexactlywhateffectafill
lighthasbyitself.
NowlookatFigure8.15,inwhichweturnedthemainlightbackon.Thisisatypicalexampleofthecombinationoffill
lightandamainlight.
8.14Allweusedtomakethisexposurewasthefilllight.Noticethatitismuchdimmerthanthemainlight.
8.15Weusedamainandafilllighttogethertomakethisexposure.
Noticethattheshadowunderthechinisdarkerthantheothershadowsintheface.Thisareareceiveslittleillumination
fromeitherthemainlightorthefill.Theshadowisnotoffensive,butitwouldbeifitwereabitdarkerorharder.Wewill
talkabouthowtokeepthatfromhappening.
Sizeisimportantwhenyouareusingfilllights.Generallyspeaking,theruleis,“thebigger,thebetter.”Asyoumight
remember,thelargeralightsourceis,thesoftertheshadowsitproduces.Thesoft-edgedshadowsproducedbyalargefill
lightarelessvisibleandlesslikelytocompetewithshadowsproducedbythemainlight.
Theuseofalargefilllightallowsgreaterfreedomindecidingwheretoplacethelight.Becausetheshadowofalargefill
lightisnotclearlydefined,thepositionofthelightis,withinawiderange,ofnoimportance.Thatmeanswecanputit
nearlyanywherethatwewillnotknockitoverandthelightingdifferenceswillbetoominortomatter.
Figure8.16showsatwo-lightportraitarrangementincludingamainlightandtwopossiblefilllights,alargeoneanda
smallone.Weareunlikelytousebothfilllights,butwecouldsuccessfullyuseeither,dependingonourpreferenceand
availableequipment.
Onefilllight,likethemainlight,usesanumbrella.Thisincreasesitseffectivesizeandsoftenstheshadowsitproduces.
Becauseitislarge,wecouldmovethefilllightaroundagoodbitwithoutamajoreffectonitsshadowpattern.Suchan
arrangementmakesiteasytovarythefilllightintensitybymovingitclosertoorfartherfromthesubject.
8.16Twofilllightalternatives.Bouncingonelightintoanumbrellaproducessofterlighting.Thesmalllight,nearthecamera,produceshardshadows,buttheyfallmostlybehindthesubject,wherethecameracannotseethem.
Alternatively,thefilllightcanbesmallifwepositionitnearandslightlyabovethecamera.Noticethatthefilllightisas
closetothecameralensaswecanputit.Suchafilllightstillcastshardshadows,butmostoftheseshadowsfallbehind
thesubject,wherethecameracannotseethem.
ReflectorCardsasFillLights
Oneofthesimplestandleastexpensivewaysofbrighteningdarkshadowsistousereflectorcardstobouncelightcoming
fromthemainlightontothefaceofthesubject.
Figure8.17usesamainlightpositionsimilartothatinpreviousphotographs,butnowawhitereflectorcardhasbeen
addedtoprovidefilllight.
8.17Inthisphotograph,lightfromthemainlightbouncedoffareflectorandontothemodel’sface.Thereitfillsinsomeoftheshadows.
Wewouldliketoshowyoutheeffectofthereflectorfillcardalone,butthisisimpossible.Becausethereflectoris
illuminatedbythemainlight,ithasnoeffectbyitself.However,itisusefultocompareitseffectwiththatofthe
additionallampinFigure8.15.Thereflectorfillisdimmer,butthetwopicturesaremorealikethandifferent.
NoticethatthedarkshadowwesawunderthechininFigure8.15hasbeengreatlyreducedbythereflectorcard.The
shadowisstillpresent,butitissofter.Thisisbecausethereflectorcardismuchlargerthanthefilllightusedearlier.We
could,ofcourse,haveusedafilllightaslargeasthereflectorcardtoproducethesameresult.
Theonlycommonproblemwithareflectorfillisthatitmaynotbebrightenoughtosuitsomephotographers'preferences.
Thisisespeciallylikelywhenwemovethecamerabacktoincludemorethantheheadandshoulders.Thereflectoralso
hastobemovedbacktogetitoutofcamerarange.
Theamountoffilllightareflectorprovidesisdeterminedbynumerousfactors,includingthefollowing:
•Thereflector’sdistancefromthesubject.Thecloserthereflectoristothesubject,thebrighterthefilllightbecomes.
•Thereflector’sangle.Areflectorcardilluminatesthesubjectmostwhenitfacesananglebetweenthesubjectandthe
mainlight.Turningitmoretothesubjectreducestheintensityofthelightfallingonit.Turningitmoretothemainlight
reflectsmorelightinadirectionawayfromthesubject.
•Thereflector’ssurface.Differentreflectorsurfacesreflectdifferentamountsoflight.Inourexample,weusedawhite
reflectorcard.Ifwehadwantedmorelightonthesubject,wecouldhaveusedasilverreflector.Remember,however,that
thechoiceofreflectorsurfacealsodependsonthesizeofthemainlight.Alargesilverreflectorfillcanbeasoftsource
onlyifthemainlightisalsosoft.
•Thereflector’scolor.Whenshootingincolor,youmayalsowanttoexperimentwithcoloredreflectorcards.Attimes
theyareusefulforeitheraddingorsubtractingshadowcolor.Inadaylightportrait,forexample,thesunisusuallythe
mainlightand,withoutreflectors,theopenskyisthefill.Theblueskyaddsbluetotheshadow.Usingagoldreflector
warmstheshadow,thuseliminatingtheblueandproducingamoreneutralcolor.Usingexactlytheoppositeapproachcan
makeastudioportraitresembledaylight.Apale-bluereflectorcoolstheshadowcolorenoughtolookmorelikethatinan
outdoorphotograph.Theeffectissubtleandfewviewerswillnoticeitconsciously;still,theyaremorelikelytobelieveit
isanoutdoorportrait.
Gobo
Kicker
Background
above
lens
Reflector
Hairlight
8.18Amainlight,reflectorfill,plusothercommonlyusedportraitlights.Althoughsomephotographersusefewerlightsandothersusemore,thisarrangementiscommon.
Becausewepersonallypreferthereflectortotheearlierstrobefill,wewillkeepitinplaceforallofthesubsequent
photographs.Figure8.18showswhereweplacedthereflectorinamorecomplexportraitlightingarrangement.
Nowletustalkabouttheotherlightsinit.
BackgroundLights
Sofarwehavetalkedaboutlightingthesubject.Backgroundlightsilluminate,asthenameimplies,thebackgroundrather
thanthepersonbeingphotographed.Figure8.19showstheeffectofthebackgroundlightbyitself.
Figure8.20wasmadewithathree-lightsetup.Besidesthemainandfilllightsweusedbefore,weaddedabackground
light.CompareitwithFigure8.17,whichwasmadewithjustamainlightandafill.
Asyoucanreadilysee,thetwopicturesaresimilar,butlookathownicelythebackofthemodel’sheadandhershoulders
areseparated
8.19Inmakingthispicture,weusedabackgroundlighttoseparatethesubject’sheadandshouldersfromthebackground.Noticehowthisaddsdepth.
8.20Addingthebackgroundlighttothefillandmainlightssurroundsthesubjectwithapleasingglow.
fromthebackgroundinFigure8.20.Thatisexactlywhatbackgroundlightsdo.
Theyprovideadegreeoftonalseparationbetweenthesubjectandthebackground.Thisseparationhelpsgiveafeelingof
addeddepthtoaportraitandsurroundsthesubjectwithwhatisoftenavisuallypleasing“glow.”Youcanbeheavy
handedwiththis,givingthesubjectapronouncedhalo,oryoucanbesubtle,pullingthelightfartherfromthebackground
orusingmultiplelightstolightthebackgroundevenly.
Backgroundlightscanalsoaddcolortoportraits.Wedothisbyattachingcoloredgels,orfilters,tothelight.Gelsarenot
expensiveandtheycomeinawiderangeofcolors.Byusingthemandawhitebackground,photographerscanreducethe
numberofdifferentcoloredbackgroundsthattheyneedtokeeparoundthestudio.Severalbackgroundlightswithfiltersof
differentcolorscancreatecolorcombinationsimpossiblewithcoloredseamlesspaperandwhitelights.
Figure8.18showsonecommonbackgroundlightposition.Thelightisplacedonthefloorandaimeduptolightenthe
background.Thisarrangementworkswellforahead-and-shouldersportrait.Hidingthebackgroundlightbehindthe
subjectismoredifficultinafull-lengthportrait.
Furthermore,lightingthebackgrounduniformly,insteadofabrightcenterspot,isalmostimpossiblewiththebackground
lightinsuchaposition.Tophotographthewholebodyortoilluminatethebackgroundevenly,weprefertousetwoor
morebackgroundlightsoneachsideofthesubject.
Backgroundlightsmaybeverybrightorverydim.Experimentuntilyoucomeupwiththelightingyoulike.Forportraits
youintendtolaterpasteintoanotherscene,trylightingabackgroundslightlylighterthanpurewhite(justtobesure).You
canthenoftenplacetheportraitintoanothersceneusingthesoftware“darken”mode.Inmanyscenes,thiseliminatesthe
needfortediouslysilhouettingthehair.
HairLights
Thenextlightthatwearegoingtodiscussisthehairlight.Thislightisoftenusedforhighlightsthatseparatedarkhair
fromadarkbackground.However,evenifthehairisblond,brighteningitwithadditionallightcanmakethephotograph
lesssomber.Figure8.21wasmadewithahairlightalonetoshowtheeffect.
NowlookatFigure8.22.Wemadeitwithamainlight,afilllight,andahairlight.Thiscombinationhasthehairlightset
atatypical
8.21Wemadethisexposureusingnothingbutahairlight.Noticethehighlightsthatitputsonthesubject’shair.
8.22Ahairlightusedalongwiththemainandfilllights.Thisoneisoftypicalbrightness.Somephotographerslikebrighterhighlights,whereasotherspreferthemdimmer.
brightness.Somephotographersmightprefertokeepitdimmer,providingseparationinthedarkareasbutattractingless
attentiontoit.Otherspreferabrighterhairlightforamoretheatricallook.
ThediagraminFigure8.18showsonecommonpositionforthehairlight,onthesideoppositethemainlightandbehind
thesubject.Alternatively,youcanuseaboomtosuspendthehairlightaboveandtotherearofyoursubject.Theboom
allowsbetterfreedomtopositionthehairlightwithoutgettingthelightstandinthepicture.
Thehairlight,likeanyotherlightcomingfrombehindthesubject,revealsloosestrandsofhair.Whetherthisisaproblem
dependsonpersonaltasteandcurrentstyle.(Somepeopleprefertolookmeticulouslytidy,whereasothersarehappytobe
absolutelyshabby.Eitherway,theirchildrenareprobablytheopposite!)Ifwedonotwanttheloosehair,wehavetouse
hairspray,anticipateretouching,orforegothehairlightentirely.
Itisimportanttopositionthehairlightsothatlightcomingfromitdoesnotproduceflare.Remembertolookatthelensas
youpositionthehairlighttoseeifthelightisfallingdirectlyintothelens.Ifitis,youmaybeabletomovethelightabit.
Ifyoudonotwanttochangethelightposition,blocktheoffendinglightfromthelenswithabarndoororagobo.The
goboabovethelensinFigure8.18servesthispurpose.
Kickers
Alongwiththedifferentlightsthatwehavetalkedaboutsofar,somephotographersalsoliketouseakickerasapartof
theirsetup.Figure8.23waslitbyakickeralone.
Asyoucansee,akickeraddsextrailluminationto,or“kicksup,”thebrightnessonpartofthefacebyprovidinganextra
highlight.Kickersareusuallyabouthalfthebrightnessofthemainlight.
Figure8.24showswhathappenswhenyouuseakickerwithamainlightandafilllight.Noticehowthekickeraddedan
appealinghighlightononesideofourmodel’sface.
Thepositionofthekickeristheleaststandardizedofanyportraitlight.Figure8.18showsonepossiblewaytopositionit.
Weplacedittotherearofthesubjectandonthesamesideasthemainlight.
Aswasthecasewithhairlights,whenyouareusingakickeryouhavetobecarefulthatlightfromitdoesnotspillintothe
lens.Ifitdoes,itwillcauseflare.ThegoboweusedoverthelenstopreventflarefromthehairlightinFigure8.18willdo
thesameforthekicker.
8.23Akickerbyitself.Kickersarelightsthataresometimesusedtobrighten(or“kickup”)asmallextrahighlight.
8.24Thekickeraddedanappealinghighlightdownthesideofthemodel’sface.
RimLights
Somephotographersuserimlightstoilluminatetheedgesofthesubject.Rimlightingisoftenacombinationofhairlights
andkickerssosimilartothearrangementsdescribedintheprecedingsectionsthatitmakesnodifferencewhichtermswe
usetodescribethelights.
However,onevariationonrimlightingisdifferentfromanythingwehaveseen.Thistechniqueplacesthelightdirectly
behindthesubjectinapositionsimilartothatofabackgroundlightbutaimsthelightatthesubjectratherthanthe
background.
Figure8.25showssucharimlightusedalone.Figure8.26isacombinationoftherimlightplusotherlights,andFigure
8.27diagramsthesetup.
MOODANDKEY
Moodisoneofthosesubjectiveideashardtodiscussandstillhardertoquantify.Itisoneofthosetermsthatoftenhas
differentmeaningstodifferentpeople.Atthesimplestlevel,wewillallagreethatpicturesthathaveadarkandsomber
lightingevokeadifferentresponsefromthosethatarelightandbrilliant.
Tokeepfromconfusingeachotherwithdifferentpersonalperceptions,photographerstalkaboutthekeyorbrightnesskey
insteadofmood.Noonefactordetermineskey.Lightingmaybethemostessentialfactor,butsubjectmatterandexposure
alsogreatlyinfluencekey.
Low-KeyLighting
Large,prominentareasofdarkarecharacteristicoflow-keylighting.Picturesmadewiththiskindoflightingtendtobe
somber—serious,formal,anddignifiedinmood.
Low-keylightingrequiresmoresideandbacklighting.Frontlightingdoesnotproduceenoughshadowareatokeepthe
keylow.Mostoftheexamplesthatyouhaveseensofarinthischapterweremadewithfairlylow-keylighting.Wedid
thisbecauseitiseasiertoseetheeffectofeachlightinamultiple-lightsetupusinglow-keylighting.
High-KeyLighting
High-keylightingisquitethereverseoflow-keylighting.Picturesmadewithhigh-keylightingarelightandbright.They
havemanywhiteandlightgraytonesinthem.Thistendstogivethemtheircharacteristicupbeatlook.Forthisreason,
photographersfrequentlyusehigh-keylightingtoproduceayouthful,happylook.
8.25Rimlightingbyitselfplacesabright“halo,”orrimoflight,aroundthemodel’shead.
8.26Arimlightalongwithamainandafilllight.Noticehowtherimoflightaroundthemodel’sheadseparatesitfromthebackground.
8.27Noticehowweplacedtherimlightinaboutthesamepositionaswemighthaveplacedabackgroundlight,onlyinthiscasewepointedthelightatthebackofthehead.
Figure8.28isofthesamemodelthatwehaveusedsofarinthischapter.Lookathowdifferenttheportraitiswhendone
withahigh-keyapproach.Itsmoodiscompletelydifferentfromthosepresentedsofar.Noticethatinthistreatment,we
havechangedmorethanjustthelighting.Wehavealsochangedthecostumeandthebackground,makingthemfar
brighterthaninthepreviouspictures.
Manyofthelower-keyportraitsyouhaveseeninthischapterusedlightingthatproducedhighlightsofonekindorthe
otheralongtheedgesofthesubject.Weneededthesehighlightstodelineatethesubject’sfeaturesandtoseparatethem
tonallyfromthebackground.Withoutthem,thefeaturesofthesubjectwouldhavemeltedintothebackground.
High-keyportraitlightingalwaysusesagreatdealoffrontlight.Edgehighlightingislessbeneficialinhigh-keylighting
becausetheedgeofthesubjectthreatenstodisappearagainstthelightbackground.Thus,wetendtoomitmanyofthe
lightsthatareimportantinlow-keywork.Itisusuallyeasiertolighthigh-keypicturesthanitistolightlow-keyones.
8.28Thepreponderanceoflighttonesgiveshigh-keypicturesafreshandbrightlook.Suchimagesarecommoninthefashionandeditorialfields.
Figure8.29showshowwearrangedthelightsforthehigh-keyexampleyouhavejustseen.Noticethatallweneededwas
onelargemainlight,areflector,andapairofbackgroundlights.Weputthemainlightabovethecamerabutascloseto
thelensaspossible.Inthisposition,itbathedthemodelinsoftandalmostshadowlessillumination.Weplacedthe
reflectorunderthecameraandclosetothemodel.Sopositioned,itbouncedsomeofthemainlightilluminationbackonto
her.Thetwobackgroundlightsturnedthebackgroundintoonelargeandevenlylithighlight.
Thissetupproducedaveryflatlightingwithfewshadowstohelpdelineatethefeatures.Thislackofshadowisboththe
advantageandthedisadvantageofsuchlighting.
Becausesuchlightingreducescontrast,ithelpstomakeblemishesandotherskinimperfectionslessnoticeable.Most
photographersconsiderthistobeflatteringandappropriatetoyoungwomenandchildren.Ifyouhaveanydoubtsabout
this,justlookatthecoversoffashionandbeautymagazines.Manyoftheimagesaremadewithlightingsimilarto
8.29Adiagramofthelightingusedfortheprevioushigh-keypicture.Boththemainlightandreflectorbathedthemodelinsoft,almostshadowless,light.Otherlightsturnedthebackgroundintoalarge,evenlylithighlight.
this.However,youshoulduse“beauty”lightingwithcare.Thelackofshadowscanalsoproducepicturesthatappearflat
andformlessandseemtobewhollywithoutcharacter.
StayinginKey
Manyphotographersconsideritagoodideatokeepaportraitdefinitelylowkeyordefinitelyhighkeywheneverpossible.
Theydonotmixlow-andhigh-keysubjectmatterandlightingtechniquesunlessthereisadefinitereasonfordoingso.
Everyoneknowsthatthisrulecannotalwaysbefollowed.Exceptionsincludeafair-skinnedblondeindarkclothingora
dark-skinned,darkhairedpersoninlightclothing.Professionalportraitphotographersoftendiscusswardrobewiththe
subjectinadvance,butmostnonphotographerswouldbeamazedathowmanypeopleagreewiththephotographer’s
adviceandthenshowupdressedexactlytheopposite.
Unlessyoucroptoincludeonlytheface,eitheroneforcesyoutomixhigh-andlow-keyelementsintheportrait.Onother
occasions,youmaydecidetomovethemainlightmoretothesidetoincreasetheshadowareainahigh-keyportraitto
emphasizefacialcontour,oryoumaydecidetominimizeshadowinanotherwiselow-keyportraittomaketheskinappear
smoother.
Nevertheless,stayinginkeyhassomemerit.Ifmostofthecompositionisinthesametonalrange,thepicturehasless
cluttertocompetewiththeface.Thisisespeciallyusefulforphotographersbeginningtolearnportraiturewhohavenotyet
learnedtofullycombinelighting,posing,andcroppingtounifythecomposition.
DARKSKIN
Weknowthatphotographyismostlikelytolosedetailinthehighlightsandintheshadows.Fewpeoplewithlightskinare
lightenoughtocosthighlightdetail,andwerarelyencountersuchproblems.However,afewpeoplewithdarkskinare
darkenoughtopresentpotentialshadowdetailproblems.
Somephotographersincreasetheexposureinthesecases.Sometimes,andwemustemphasizeonlysometimes,this
strategyworkswell.If,forexample,thesubjectisdarkskinnedandwearingadarkshirtandcoat,itissafetoopenthe
lensconsiderablytocompensateforthelightlostbyskinabsorption.
However,ifthesubjectisabridewithverydarkskininawhiteweddingdress,theprecedingstrategycouldleadto
disaster.Thefacewouldstillbeproperlyexposedandhavegoodshadowdetail,butthedresswouldbehopelessly
overexposed.She'sbeenanticipatingportraitsinadresswiththisdelicatelacedetailfor20years,andyou'reintrouble!
Fortunately,thereisabetterwaytoapproachthisproblemthanjustopeningtheapertureandhopingforthebest.Thekey
tosuccessfullydealingwithdarkcomplexionsistoincreasethedirectreflectionsfromthem.
Humanskinproducesonlyasmallamountofdirectreflection,butasyoumightremember,directreflectionismostvisible
onadarksurface.Therefore,capitalizingondirectreflectionisonewaytolightendarksubjectswithoutincreasinggeneral
exposure.
Anotherpointtokeepinmindisthatthelargerthelightsource,thegreaterthegroupofanglesfromwhichitslightwill
strikethesubject.Thisenablesalargelighttofillmoreofthefamilyofanglesthatcausesdirectreflection.Thus,ina
portraitofapersonwithdarkskin,alargerlightproducesalargerhighlightontheskinwithoutadjustingtheexposureat
thecamera.
Beaware,however,thatjustaslightincreaseinthesizeofthelightwouldofferalmostnoimprovement.Becauseahuman
headisroughlyspherical,thefamilyofanglesthatproducesalargedirectreflectionis
alsoquitelarge.Thelargerthelightweuse,thebettertheresult.Wemaystillhavetoopentheapertureabit,butnotvery
much,andboththebride’sfaceandherdresswillphotographwell.(Ifyouarenotreadingthesechaptersinorder,we
suggestyoulookbackatFigure6.29,roundmetal,orFigure7.10,glass,toseethefamilyofanglesofdirectreflectionon
aroundobject.)
AVAILABLE-LIGHTPORTRAITURE
Fromtimetotime,youoryourclientwilldecidethataportraitneedstobemadeawayfromthestudio.Location
portraiturecanbecompletelyfrustratingifyouareusedtothecommandthatthestudiogivesyou.Itcanalsobe
fascinatingandenjoyable.Furthermore,theenvironmentcanbeanessentialpartofthepersonand,therefore,ofthe
portrait.
InChapter10wewilldiscusstheuseofminimallightinggearonlocation.Thosetechniquesareimportant,andtheyapply
equallytoportraitureaswellastootherphotographicspecialties.Sometimeslogisticsorotherconsiderationsmakeit
impracticaltouselarge,heavy-dutylightinggear.Andsometimesweareevenmorechallenged—wecannotuseanylights
atall.We,inotherwords,eithergetthepicturesweareafterwithnothingmorethantheambientlightpresentwherewe
shoot,orwedon’tgetthem.
Withthatinmind,wewillfinishthischapterwithabrieflookatsomeusefulambientlightandambientlightplusflash
portraittechniques.Wehaveomittedadetailedtreatmentofavailable-lightportraiturebecausethemethodsresemble
studioportraituremorethantheydiffer.
Wewillofferjustenoughexamplestoillustrateacardinalrule:locationorstudio,theguidingprinciplesarethesame.Itis
thatsimple.Nomatterwhereyouare,outsideorinside,cornfieldorstudio—lightislight.Itfollowsthesameimmutable
lawsofphysics.Inthenextfewpages,wewilllightourmodelsaccordingtothesameprinciplesaswewouldinthe
studio.OnlythistimewewillbelookingforMotherNaturetoprovidemost,ifnotall,ofthelight.
AWindowasaMainLight
LookatFigure8.30.Itisatypicalexampleofawindow-litportrait.Thisbasicpicturehasbeenrepeatedmanytimesby
manyphotographers,andforgoodreason.Asyoucansee,softlightstreaminginthroughthewindowgivesgoodcontour
anddepthbutnoneoftheharshnesssometimesseeninportraitsthatweremadewithdirectdaylight.
Aspleasingasthispictureis,thelightinginvolvesnothingnew.Thekeytoitssuccessisalreadyfamiliar.Largelight
sourcesproducesoftlighting.Inthestudio,weusealargediffuseroranumbrellaforalight
8.30Softlightfromtheopenskystreaminginthroughawindowmadethisportrait.Thesoftandpleasinglightiswellsuitedforthesubject.
source.Onlocation,theskyisourlargelightsource.Thetoolsaredifferent,buttheresultisthesame.
Youmustremember,however,thatthewindowdoesnothaveanymagicqualitiesthatinevitablymakeitasoftlight
source.Figure8.31provesthispoint.Ourmodelisinthesameplace,andsoisthewindow,butlookatthedifference.
Inthesecondpicture,hardshadowscompetewiththesubject'sfeatures.Itcouldstillbeagoodpicture,dependingonthe
intent,butitisnotaflatteringportrait.Whatcausedthedifference?Simplyput,theanswerislightsize.Thetwopictures
weremadeatdifferenttimesofday,andthesunhadmovedduringthetimebetweenthem.
Inourfirstpicture,thelightthroughthewindowwasfromtheopensky.Theskyisalargelightsource.Thesecond
photographwasmadelaterintheday,whenthesunhadmovedacrossthesky.Itwaslitby
8.31Laterintheday,thesunwaslowerinthesky,anditsdirectraysproducedtheharshshadowsthatweseehere.
directsun,andasyouknowbynow,thesunalwaysbehaveslikeasmalllightsource.Directsunlightalwaysproduces
hardshadows.
So,onceagain,wehaveseenthatstudioorlocation,sunorstrobe,theresultsarethesame.Lightislight.Largelights
producesoftshadows,andsmalllightsproducehardones.Thelocalemaychange,butthebehavioroflightdoesnot.
TheSunasaHairLight
Figure8.32showsanoutsidesetup.Weareincludingittoshowhowyoucanduplicateastudiomainlightandhairlight
setupinthefield.
Figure8.33showshowthispicturewasshot.Theopenskyservesasalarge,softmainlight.Whenwemadethispicture,
thesunwasjustoverthetopofthebackgroundtrees.Sopositioned,itmadeaperfecthairlight.Noticealsohowthedark
treesinthebackgroundcontrastwellwiththebrightlylithair.
8.32Outsidenaturallightandareflectorproducemuchthesamelookasdomainandhairlightsinthestudio.
8.33Hereweseehowwemadethepreviousshot.Noticethattheskyservesasalarge,softmainlight.Thesunwasjustpeepingoverthetopofastandoftreesinthebackground,andwepositionedthemodelsothatitactedasahairlight.
Onceagain,thelocationwasdifferent,buttheprinciplesthatwefollowedwerethesame.Onceagain,lightbehaveslike
light!
CombiningPortableandAmbientLight
Sometimesambientlighthasabeautytotallyunexpectedbecauseit'snothingwewouldbeabletotrulyreproduceinthe
studio.Unfortunately,however,insomeofthosesamecases,thelightweencounteronlocationisnotadequate,byitself,
tomakeafullyacceptablepicture.Wewillcontinuethischapterbyexaminingsomesuchsituations.
InFigure8.34therewasalarge,highwindowthatsomephotographerswouldbetemptedtouseasamainlight.Instead,
werealizedthat
8.34Inmakingthispicture,weusedthenaturalambientlightthatproducedboththekickerandthehairlight.Inadditionweaddedfilllighttothescenefromaflash-fittedumbrellathatwepositionedclosetoourcamera.
thiscouldbethebiggesthairlight-kicker-rimlightwe’deverhadthechancetouseandpositionedthesubjectaccordingly.
Asilverumbrellaaboveandtotherightofthecameraprovidedfill,butinthiscaseasmallstrobeonthecamerawould
haveworkedalmostaswell.
Figure8.35isanother,butquitedifferent—andconsiderablymoreluminous—exampleofaportraitshotmadeusing
mixedlightsources.Wemadethisshotusingbothportablestrobesandtherich,warmlycoloredambientlightpresentat
thescene.Inaddition,forthispicture,weaddedagreengeltoourbagoftricks.ThesubjectisMissPrissyPistol,a
burlesqueartistinthevenuewheresheperformed(Figure8.35).
8.35Thisportraitisanexampleoftheeyecatchingluminosityand“punch”itispossibletoachievebymixingflashandmixed,brightlycolored,ambientlightsources.
8.36ThisdiagramshowsthesetupweusedtomakeMissPrissy’son-locationmixedambientlightandflashportrait.
Forourkey,ormain,lightwechosearound22-inch“beautydish,”orasit’ssometimescalled,“softlight.”Weplacedthis
lightabove,andtocameraleft,ofourcamera(seeFigure8.36).
A32-inchverticalstripboxplacedtocamerarightofourcameraandaimingupfromtheflooraddedabitofextrafill
lighttothecamerarightsideofMissPrissy'sfaceandtorso.
Forthethirdlight,wetapedagreengeloveraflashheadandaimedintoa36-inchumbrella.Wethenputthisabout7feet
behindMissPrissyandtocameraright.LightfromtheumbrellaaddedtheslightgreenkickyouseeonMissPrissy's
camerarightarm,shoulder,andhair.Italsoaddedsomeadditionallighttothebackofthebar.
Whenitcametimetoshoot,wesetourcameraapertureati/5.6withanISOof100.Wethen—afterfiringoffanumberof
testshots—selectedashutterspeedof1/6ofasecond.Atthisslowspeed,ourcamera'sshutterremainedopenlong
enoughforthevariedandcolorfulambientlightpresentinthebartoberecordedbythecamera'ssensor.
Inaddition,theflasheswehadpreviouslysetupalsoilluminatedMissPrissy.Theyfiredforthebriefestmomentwhenthe
camera’sshutterfirstopened.Called“draggingtheshutter,”thistechniquecan
produceout-of-the-ordinaryresultsandisonewithwhichitiswellworthexperimenting.
Note:Youwillneedtoturnoffyourmodelinglightintheflashheadtoavoidtheadditionalambientlightitproduces.
AReflectedAmbientLightPortrait
Workingwithambientlightcanbechallenging.Andthatisputtingitmildly!Youareneverreallysureofwhatitisgoing
tobelikeuntilyouarriveatyourshootinglocation.Inaddition,ambientlightcan,andoftendoes,changeinintensity,
color,direction,andanglewhileyouareshooting.
Withthatinmind,wehumblysuggestthateveryphotographerwhoworksusingambientlightshouldadoptthefollowing
motto:“It’swhatyoudowithwhatyou’vegotthatcounts.”TheportraitinFigure8.37,takeninSavannah,Georgia,isa
caseinpoint.
Photographyisnodifferentfromtherestoflife.Sometimeswearelucky—asinverylucky—andeverythinggoesright.It
wasononeofthosealltooinfrequentdaysthatthereflectedambientlightwasusedinanunusualsetting,abus,toshoot
thefollowingeyecatchingportraitoftheyoungmansittingacrosstheisle.
8.37Thisyoungman’sportraitwasmadeusingnootherlightsourcebuttheambientlightthatwasreflectedintothebusfromthepavementandtherestofitssurroundings.
Themorningonwhichthisportraitwasmadewasbrilliantlysunny.Thebus'sinteriorwasawashwithlightthatwasbeing
reflectedofftheparkinglotandintothebusthroughitsmanywindows.
Onceinside,thislightcontinuedtobereflectedandre-reflectedfromoneshinysurfacetoanother.Theresultwasavirtual
“sea”ofbrightambientlightswirlingaboutthebus'sinteriorandwrappingaroundtheyoungmansittinginhisseat.
Theresultspeaksforitself:anarresting,high-keyportraitofayoungmanlitwithnothingbuttheintensesunlightreflected
intoabusfromthepavementonwhichitwasparked.
APPROACHESWORTHTRYING
Beforeweendthischapter,wewouldliketointroducethreemoretechniqueswefindbothusefulandinteresting.Thefirst
involvestheuseoftwolights—onelargeandonesmall.Theotheremployscoloredgels.Andthethirdreliesonmotion
foritsimpact.Noneisparticularlycomplextoexecute.Allareusefultoolsworthaddingtoanyone’slightingarsenal.
UnfocusedSpot
WhenmakingFigure8.38,ouraimwastocreateadramaticportraitinwhichoursubject'sfacestoodoutbrightlyfromits
somber,almost
8.38Wecombinedthelightgivenoffbyalargebanklightwiththatofaseven-inchtightgridspottoilluminateourmodelgenerallyandhighlightherface.
8.39Thisdiagramshowsthe“additive”lightingsetupweusedtomakeFigure8.38.
monochromatic,setting.Tomakethepicturewewanted,wedecidedtousetwoverydifferentlightsources(Figure8.39).
Onewasa54-by-72-inchbanklight;theotherwasatightgridspotfittedtoa7-inchreflector.Priortoshooting,weasked
ourmodel,Farrah,towearaneutraltonedgrayjacketthatwouldcomplementthesteelyblue-tonedbackgroundwehad
previouslyselected.
Whentimetoshoot,weputthelargesoftboxtoourcameraright,aboutafootinfrontofFarrah.Sopositioned,itput
noticeablymorelightonthecamerarightsideofherface,thushelpingtodelineateherfeatures.Wethenplacedourgrid
spotcloseto,anddirectlyinfrontof,thebanklight.ThisproducedacloselydefinedandintensespotoflightonFarrah’s
face.
Oncewecompletedoursetup,wemadeaseriesoftestshotsvaryingourexposuresettingsandtheoutputofthetwolights
wewereusing.Afterseveral,weselectedthecombinationthatproducedtheimagewehavepreviouslyshownasFigure
8.40.
Forthesakeofcomparison,intheillustrationthatfollows,weshowwhatFarrahlookedlikewhenlitwitheachofthetwo
lightsweusedtomakeherfinishedportrait.
B
8.40Ontheleft(A),weseeFarrah’sfacelitbythegridspotalone.Ontheright(B),weseeherfacelitbyonlythebanklight.
A
SmallLight?LargeLight?WhyNotBoth?
We’veseentheadvantagesofasmalllight:crisplydefinedshadow,goodtextureinsubjects,whichrevealthattextureinmostlydiffusereflection.
We’vealsoseentheadvantagesofalargelight:shadowssoftenoughthattheydonotdistractfromtheprincipalsubject,theabilitytofillalarge
familyofanglestorevealthesurfaceofaglossysubject.
Whatifwewantbothatonce?Wecancertainlydothis,andthereareseveralwaystoaccomplishit.Oneisessentiallycost-free,assumingwe’re
alreadyreasonablyequipped;anotherisfairlyexpensive,butfarquickerandeasiertoreposition.Thedifferenceineffectmaybefairlysubtle,
dependingonthesubject.Tryallthree,ifyoucan,withborrowedequipment,andthendecidewhichyouwanttomostlyuse.
ASmallLightPlacedVeryClosetoaBigPieceofDiffusionMaterial
Thelightdoesn’tilluminatethewholediffusionsheetevenly.Therewillbeahotspotinthecenter,servingasafairlyhardlight.Therewillalsobe
lightscatteredtofillthewholesheet;thatgivesusoursoftlight.Essentially,wegettwodifferentlightsfromoneelectronicdeviceandwegetvery
goodcontrol:movethelightclosertothediffusionmaterialtoincreasethehardlight;movethelightfartherfromthediffusionmaterialtoincreasethe
softlight.Thedisadvantage:we’retalkingaboutaprettybulkyarrangementhere.Thereareprobablytwostands,plusaconnectingrodtoholdthe
diffusionmaterial,thenanotherstandforthelight.
Onephotographercanmanageallofthiswithpractice,butanassistantspeedsthingsup.Thephotographermovesthepivotalstandholdingthe
diffuserandthentellstheassistantwheretoputtheotherstand(“No,notquite,sixinchesclosertothesubject.Yes,there!”).Thenwehaveto
repositionthelight,assumingwehavethediffusionmaterialintherightplace.Difficulttolearn?No.Practicerequired?Definitely,butthefactthat
youhavereadthisfarintothisbookprobablyprovesthatyouareoneofthosewhointendstoputtheextraeffortintoyourlighting.
BackuptheLightbehindtheDiffusionMaterialandThenPutaSecondSmallLightinFrontofIt
Nearlythesameeffectasmethod1butmorecontrollablebecausewecanadjustthepowerofthetwolightsindependently.
AnotherApproachIstoUseaBeautyDish
Abeautydishisametalreflectorsimilartomanyotherstudiostrobereflectorsexcepttheyarequitelarge,usually20to30inchesindiameter.The
largereflectoractsasasoftlight;thesmallerflashtubeactsasahardlight.Afewhaveoptionalcoversfortheflashtubeforsofterlight:sortofa
beautydish-softboxcombinationeffect.Theyrequireonlyonestandinsteadofthethreeorfourneededbytheothermethods,soonephotographer
caneasilycontrolthem.Soundslikeawin-winsituation,right?Notquite.Theydonotfoldupfortravellikeanumbrellaoraclothsoftboxandthey
areprettyexpensive.Still,ifyouarealreadywellequippedandyoudomostofyourworkinthestudio,buyingabeautydishmaybethenextstep
foryou.
OntheleftweseeFarrahilluminatedbyjustthegridspot.Onlythebanklightwasusedtomaketheimageontheright.
ReferringbacktoFigure8.38weseetheimpact—theadditiveeffect—thatresultedwhenwecombinedthesetwovery
differentlights.
CombiningPortableFlashwithColorGels
Ourlivesarefilledwithcolor—afactthatwe,asphotographers,areallwellaware.Muchofthetimeourroleas
photographersistorecordthesecolorsjustasweseethem.Inotherwords,ourpurposeisto“getthecolorsright”—thatis,
toshowthemasclosetorealityaswecan.WemadeFigure8.41,aportraitofourfriend,Tony,withthatapproachin
mind.
Tomakethepicturewehadinmind,weusedthreeportablestrobesofthe“hotshoe”varietymadebyNikon,Canon,and
othermanufacturers.Eachoftheseflashescouldbecontrolledwirelessly,eitherseparatelyorasagroup.
8.41Tonyasseenwhenlitwith“normal”coloredlights.
PositionedbehindTony,weusedhisfirstportablestrobetolightthepicture'sbackground.Wethenplacedoursecond
strobetoTony'scameraleftanduseditasakickertoaddthestronghighlightvisibleonthatsideofTony'sface.
WethensetourlastlighttofireintoanumbrellathatweplacedonTony’scamerarightside.Fromthereitlitmuchofhis
faceanduppertorsowithasoft,diffusedlight.
Asyoucansee,thisarrangementproducedaclassicexampleofa“naturally”or“faithfully”coloredportrait—aportrait
thatshowsTonyascloseaspossibletothewayheactuallywaswhenthispicturewasmade.Andthat'sfineifthat'sthe
imageyouwant.Butwhatifthatisnotthekindofpictureyouwanttomake?Whatif,instead,youwanttomakeaportrait
thatisabitdifferent?Whatifyouwanttoaddsomethingextraoroutoftheordinarytothewayyoulightit?
Well,onethingyoucantryistoaddsomecolortothelightyouuse.Andthatiswhatthenexttwopictureswill
demonstrate.Wewillbegin
withFigure8.42.Weusedexactlythesamelightingarrangementtoshootitthatwedidtotaketheprevious“normal”shot
ofTony.
Thistime,however,wetapedpiecesofamberfiltermaterial—orasitisgenerallyknown,“gel”—onbothourbackground
lightandourkicker.Andwhatadifferencethatmade.Thisimage,whilemadewithexactlythesamelightingweused
before,sendsaverydifferentmessage.Andwhatisitthatproducedthisverybigdifferencebetweentwoalmostidentical
portraits?Theanswerissimple:color—thecolorproducedbythepiecesofambergelweattachedtoourlights.
Well,nowthatwehaveseenTonyinbothhisnormalandambermodes,letusmoveontoourfinalexampleofcolorin
action.Figure8.43kicksTony'sportraitupanotchbyaddingtwocolors—greenandblue—ratherthanjustone.
Weusedthesamethree-lightsetupthatweusedbeforetomakethisimage.Onlythistimeweaddedbothgreenandblue
gelstoit.Todothis,wegelledbothourbackgroundlightandourkickerwithgreen.Inaddition,weattachedabluegelto
thelightthatfiredintoourmainlight.Together,theyproducedwhatIthinkisaninteresting,andeyecatching,mixedcolor
effect.
Asweshowedinthepreviousthreepictures,usingcoloredgelstoaddcoloredlightstootherwise“normally”madeshots
canproduceinterestingresults.And,fortunately,thisisnotacomplextechniquetoaddtoyourlightingrepertoire.Itis,
however,onethattakessomepractice.Youcanneverbecompletelysurewhattheexactresultisgoingtobewhenyouuse
evenonegel.Useseveral,andthingsgetevenlesspredictable.
Thenthereisthequestionofexposure.Ortoputitanotherway,justhowmuchlightmusteachofmyflasheshaveto
pumpouttoproducethelookIwant?Obviously,thiscanrangewidelydependingonsuchvariablesaswhatcolorsand
howmanydifferentonesyouuse.
Lastly,ifyouplanonusingremotedevicestocontrolyourflashes,thereisthemysteriousartofgettingthemtowork
properlytobemastered.Theirmanufacturerswillassureyouthisispurechild'splay.Well,don'tyoubelievethemforone
minute!Ihavewitnessedmorethanoneexperiencedshooterlapseintofitsofrageapproachingtemporaryinsanitywhile
tryingtogetabunchofremotelyconnectedflashestoworktogether.
Andwhatdoesallthismean?Simplyput,itmeansthatthekeytogettingcoloredlightstoproducetheresultsyouwantis
experimentation.Inotherwords,shoottestshotaftertestshotuntilyougettheresultsyouwant.Thismaysoundlikea
trulyprimitivewayofgoingaboutthings.Andperhapsitis.Butitworks.SometimeagoIhadthepleasureofwatching
JoeMcNally,oneofthemostexperiencedand
8.42Tonylitusinganambergel.
8.43Tonylitusingbothgreenandbluegels.
soughtafterphotographersworkingtoday,makesomecomplex,remotelylinked,multilight(severalofwhichweregelled)
shots.
Andhowdidhedothem?Well,hedidjustwhatwesuggestedhere.Hesetuphisgearandthenstartedshootingtestshots.
Aftereachhewouldadjustsomething—beitwherealightwas,howhotitsflashwas,thecolorofagel—untilhewas
happywiththeshot.Now,ifthatiswhatittakesforoneoftheworld’smostaccomplishedphotographerstopulloffa
complexshot,donotfeelbadifyouhavetodothesame!
PortableFlashwithMotion
Wehavefollowedadifferentpathinthemakingofthischapter’slastpicture.Uptothispoint,theexampleswehave
shownhavebeenabitontheseriousside;abitformalandbuttonedup.Thatisdefinitelynotthecasewiththefollowing
portrait,acompositeimageweshouldprobablycall“VanceonaRoll.”
LeadsingerandfrontmanoftheinfamousrockbandTheFactory,ourfriendVanceisblessedwithaseeminglylimitless
storeofrawenergy.Andthatisexactlywhatwewantedtoshowwhenwemadethismulti-imageportraitofhimdoinghis
action-packedthing(Figure8.44).
WeshotVanceinatunnelrunningbetweenrailstations.Wepickedthislocationbecauseofitsclose-togetherwalls,
overall“seedy”look,andthevaryingcolortemperaturesofthedifferentfluorescentfixturesthatprovidedtheambient
lightinit.
Theapproachweusedformakingthisportraitissimpleenough.Thatbeingsaid,however,itisalsoanapproachto
portraiturethatiscapableofproducinganendlessarrayofwildlydifferentresults.Theequipmentweusedwasalsothe
soulofsimplicity—acameraonwhichwemountedanon-cameraflashtowhichwehadattachedasmallportable
diffusionbox.
Ourshootingtechniquewasequallyuncomplicated.WechooseanISOof160andexperimentedwithdifferentapertures
rangingfromi/6.3tof/11.
Whenshooting,weaskedVancemoveinhisusualfrenetic,rock-and-rollstyle.Ashedid,wemademultipleexposures,
eachtimeusingtheflashandwithourcamerasetatverylowshutterspeedsthatrangedfroma1/4toa1/2second.
Sometimesweheldourcamerarocksteady.Atothertimeswemoveditaboutindifferentwaysasweshot.
Eachtimewepressedourshutterrelease,theflashwehadmountedonourcamerafired.Theveryshortburstoflightfrom
itfrozethatpartofVanceonwhichwewerefocused.
8.44Wemadethefourimagesinthiscompositeportraitbymixingthelightfromanon-cameraflashwiththeambientlightpresentwhereweshot.
However,becauseoftheslowshutterspeedswewereusing,thecamera’sshutterstayedopenforabriefperiodafterthe
flashwentoff.Itwasthenthatourcamera'ssensorrecordedtheambientlightfromVance'ssurroundings.Becauseof
Vance’smovement—orbecausesometimeswepurposelymovedourcameraindifferentwayswhileits
shutterwasstillopen—thisambientlightwasrecordedasrandomlysweepingswirlsofmixedcolors.
Needlesstosay,becauseseveralfactorsareinvolvedinthiswayofshooting,onecanneverbesureofexactlywhatthe
resultsaregoingtobe.Soshoot,shoot,andshootsomemore.Experimentationisthenameofthegame.Themoretries
onemakes,thebetterthechancesarethatatleastsomeofthemwillwork.
Thismethodmaysoundabitcomplex,butactuallythiskindofshootingiseasytolearn.Sohavesomefunandtryit.
Whenyoudo,rememberjustacoupleofthings:theflash(becauseitissobrief)freezeswhatitisaimedat,andtheslow
shutterspeedallowstimeforthecamera’ssensortorecordambientlightfromthescene.Together,thesetwovery
differentlightsourcescancombinetoproducesomeeye-catchingimages.
ANDFINALLY...
Theonlyoccasionswhentheprinciplesoflocationlightingandstudiolightingdifferarewhenaparticularlightingis
essentialtotheenvironmentortheevent.Achildblowingoutbirthdaycandles,afirefighterlitbytheharshredlighton
theengine,andanorchestraconductorinstagelightingaretheworstpossibleexamplesofgoodportraitlighting.
However,innoneofthesecaseswouldweimprovetheportraitwithstandardstudiolighting.Whenthelightispartofthe
story,wegainmorebycapitalizingonitthanbytamperingwithit.
SuggestionsYes—“Rules”No
Everythingwetellyouinthischapteristrue.Anditallworks.However,thatdoesnotmeanyoushouldfollowour
suggestionsasthoughtheyaretheonlypathstosuccessfulportraitmaking.Farfromit.Thereisnotasingletechnique
herethathasnotbeensuccessfullyandpleasinglyviolatedatonetimeoranother.
Forexample,werepeatedlyrecommendalargelightsourceforportraiture.Usingalargelighttosoftenshadowstendsto
makepeoplelookprettier,butthisdoesnotmeanthatlargelightsourcesinevitablyproducethebestportraits.Less
flatteringlightingcangivetheappearanceofdignity,wisdom,orendurance.
Iftheindividualwearephotographinghappenstobethepersonpayingfortheportrait,weusuallywantthepersontolook
asattractiveaspossible.Butwearemorelikelytopleaseamagazinepictureeditorwithaportraitthatshowscharacterand
emphasizeswhateverpersonalqualitiesrelatetothetext.
Thesizeofthelight,alongwithmostoftheothersuggestionswemake,ismorethanatechnicaldecision.Sometimesitis
artistic:Howdoesthemakeroftheimagewanttorepresentthesubject?Oftenitispolitical:Whoisthepictureintendedto
please?Alwaysitisadecisiontomakeratherthanalawtoobey.Theapproachtolightingpresentedinthischapterisa
basicapproachthatmostphotographerswillbenefitfromlearning—notasetofrulesthateveryphotographerneedsto
follow.
9
TheExtremes
Theextremesarethelightestandthedarkestgroupsofgraysorcolorsinthephotograph.Foryearstheywerethepartsof
thepicturemostlikelytolackqualitybecauseoftheinherent,irremediabledefectsinfilm.Goodphotographersmanaged
togetexcellentpicturesanywaybecausetheypaidalotofattentiontothesedefectsandhowtominimizethem.
Theextremesareapotentialprobleminanyphotograph,butinawhite-on-whiteorablack-on-blackimage,pictures
composedentirelyoftheextremes,littledefectscanturnintobigones.
Digitaltechnology,lackingsomeofthefilmdefects,haseliminatedsomeoftheseproblemsbutrevealedanewone:some
peoplelikethese“defects.”Ifweshootatechnicallyperfectpictureandreproduceitwell,wethinkitlooksdulland
unappealing!Thus,wehavetoreintroducetheclassicdefects,theoneswealwayshopedtosomedayavoid,justtogeta
picturethatlooksright.
Whenwetalkaboutwhatpeoplelikeanddon'tlike,itsoundsasifweareplayingtopopulartaste—stuffthatcould
reverseitselfinayearorageneration—butwe'renot.Theselikingsseemtobehardwiredintothehumanbrainandwill
notchangewithoutafewmorehundredsofthousandsofyearsofevolutionor,possibly,thesurgicalimplantingofdigital
eyesandlearningtousethem.Inthischapterwearegoingtotalkaboutwhatthosedefectsare,howwereintroducethem
intothedigitalimage,andhowweminimizethelossinquality.
THECHARACTERISTICCURVE
Inthisbook,wegenerallykeepourattentiononlightingandstayawayfromextensivediscussionofbasicphotography.
Nevertheless,thecharacteristiccurvedictatessomeofourtechniquewhenwelight
black-on-blackorwhite-on-whitesubjects,sowehavetotalkaboutit.Otherwritershaveexplainedthismaterialinmore
detail.Youmaygivethissectionasmuchoraslittleattentionasyouneed,dependingonwhosebooksyouhavealready
read.
Characteristiccurvesareusedinmanytechnicalfieldstoplottheresponseofonevariabletoanother.Inphotography,the
characteristiccurveisagraphofthewaythebrightnessofarecordedimagevarieswithdifferentamountsofexposureto
light.(WeareusingthenontechnicaltermbrightnesstomeanboththeelectricalresponseoftheCMOS[complementary
metaloxidesemiconductor],CCD[charge-coupleddevice],andthedensityoffilm.)Forsimplicitywewilltalkabout
grayscalecurves.Whateverwesayherealsoappliestocolor,exceptthatcolorrequiresthreecurves—oneeachforred,
green,andblue(or,forfilm,cyan,magenta,andyellow).
ThePerfect“Curve”
Thecharacteristicscurveisawaytocomparetwograyscales:onerepresentingexposurestepsinthesceneandtheother
representingbrightnessvaluesintherecordedimage.
Notethatwhenwetalkaboutcharacteristiccurves,exposuremeanssomethingslightlydifferentfromwhenwetalkabout
makingapicture.Photographersshootingpicturestalkaboutexposureasifthewholeimagereceivedasingleuniform
exposure—forexample,f/8at1/60second.Exposureusedthiswayisconvenientshorthandfor“HowIsetmycamerafor
thissubjectunderthislightingcondition.”
Butphotographersalsoknowthatideallyeachshadeofgrayinthesceneisrepresentedbyauniquevalueintherecorded
picture.Assumingwearenotphotographingablankwall,therecordedimageisagroupofexposuresthatmakeanimage
ofthegraysinthescene.Therefore,whenwetalkaboutexposurestepsinthecharacteristiccurve,wemean“thewhole
scene,”andnotnecessarilyalargenumberofrecordedpictureswitharangeofdifferentexposures.
Figure9.1showswhatmighthappenwhenwerecordascenecontainingagrayscalemadeupof10steps.Inthisgraph,
thehorizontalaxisrepresentsexposuresteps,thegraysintheoriginalscene.Theverticallinerepresentsimagesteps,
groupsofgraysintherecordedimage.
Eachexposurestepisthesamelengthonthegraphasanyotherexposurestep.Thisisnoaccident.Photographersand
scientistswhoinventedthescaledeliberatelydecidedtodividetherangeofpossiblegraysintoequalsteps.However,the
sizeofcorrespondingbrightnessstepsinthefinalimagemaynotbeequaltooneanother.Thisdifference
9.1Aperfect“curve”:anychangeinexposurewouldproduceanexactlycorrespondingchangeintherecordedimage.
inthesizeofthestepsisexactlywhatthecharacteristiccurveisdesignedtograph.
Theimportantcharacteristicofanidealimageisthatallitsstepsarethesamesize.Ifyoumeasurethelengthofthe
verticallinemarked“step2,”forexample,youwillfindittobethesameasthelengthmarked“step5.”
Thismeansthatanychangeinexposurewillproduceanexactlycorrespondingchangeinthebrightnessoftherecorded
image.Forexample,Figure9.2isagraphofthesamescene,shotwithanidealdigitalsensor(oranidealfilm)withthe
exposureincreasedthreestops.
Later,ifwedecidetheimageistoolight,wecansimplydarkenit.Ifanidealdigitalsensorexisted,exposingitwouldbe
easy.Anyphotographerwhohadanydoubtabouttheidealexposurecouldbesafeinsimplygivingmoreexposurethan
necessary.Theresultingimagecould,with
9.2Anidealcurvewithexposureincreasedbythreestops.Afterpostproductioncorrection,itcouldprintthesameasthepreviousonebecausetherelationshipofthedensitystepsisthesame.
manipulation,produceaprintwiththesamegrayscale.(Furthermore,aslongaswearetalkingaboutideals,wemightaswellassumethefilmgrainwouldbefinealso.)
Intherealworld,however,exposureisamorecriticaldecision.Thisisbecausethegraphofdensitystepsinarecordedimageisnotastraightline;it’sacurve.
ABadCamera
Photographersalmostneveruseadiagramofacharacteristiccurveintheirdailywork,buttheykeepamentalimageoftheshapeofacurvewiththemalwaysbecauseithelpsthemprevisualizehowarealscenewillappearinthepicture.Furthermore,thismentalimageslightly
9.3Inabadcamera,boththehighlightsandtheshadowsaregreatlycompressed.
exaggeratestheproblemsfoundinreality.Wewillcallthisexaggeratedexamplea“bad”camera.
Figure9.3showsthecharacteristiccurvewewouldgetfromabadcameraifweexposeditliketheidealoneinthefirstexample.Theexposurestepsshownonthehorizontallineareidenticaltothoseinthefirstgraphbecausewearephotographingthesamescene,butlookwhathashappenedtotherecordedbrightnessontheverticalline.
Steps1to3occupyverylittlespaceonthebrightnessscale;likewiseforsteps8through10.Theshadowsandthehighlightshavebeengreatlycompressed.Compressionmeansthattonesthatwereverydifferentandeasytodistinguishinthescenearenowverysimilaranddifficulttodistinguishinthephotograph.
Figure9.4isanormallyexposedscene.Thebuildingwallislargelycomposedofgray/browntones,butthelateafternoonlightgivesusawiderangeofhighlightsandshadowstostudy.Noticethatindividual
9.4Asceneexposednormallyhassomecompressioninboththeshadowsandthehighlights,buttheproblemsarenotobvious.
stonesarefaintlyvisibleinboththehighlightandshadowareasofthewall.Thereissomecompressioninboththosehighlightsandshadows.
Overexposure
Keepinmindthatinanaveragescenewithanormalexposure,compressionoccursatbothextremesofthedensitygrayscale.Changingthegeneralexposuredecreasescompressionatoneendofthegrayscale,butitworsensthecompressionattheotherextreme.Figure9.5showsthebenefitsandthesacrificesofoverexposure.
Aswecansee,increasedexposureeliminatessomeoftheshadowcompression.Thisisgood,butthehighlightcompressionismademuchworse.Let’sseewhatmighthappenifweoverexposetheearlierbuildingtosuchadegree.
Figure9.6istheresult.Weseeimprovedshadowdetailinthefloorsofthebalconies,buttherestofthepictureismuchtoolight.Thatisonlypartoftheproblem,however.Wecanfixthatpartbymakingtheimagedarkerinpostproduction.
Let’slookataFigure9.7toseewhatwouldhappenifwedidthat.Nowthemiddletonesaresimilartothoseintheearlierprint.However,
9.5Overexposureeliminatescompressionintheshadowtonesbutatthecostofmakingthehighlightcompressionmuchworse.
wecannotremedythecompressioncausedbyoverexposingthepicture.Thedistinctionswithinthebuilding’sfacadearestillnotwelldelineated.Althoughthehighlightsaredarkerinthisversion,thedetailinthemisnotimproved.
Notice,however,thatthisterriblepictureisnotwithoutvirtue.Overexposureputdetailintothedeepestshadowsthatsurvived,eveninthedarkerprint.
Underexposure
Iftheimageisunderexposed,weseesimilarproblemswiththeshadowtones.Figure9.8isthecharacteristiccurveforanunderexposedpicture.
Figure9.9issuchanimage.Thehighlightstepsarebetterseparated.Inotherwords,eachstepappearsmoredifferentfromthestepsaboveandbelowit.Whetherthistechnicalimprovementismore
9.6Thesamescene,greatlyoverexposed.
9.7A“correction”oftheoverexposedphotographofferslittleadditionaldistinctionbetweenthehighlights.
9.8Thecharacteristiccurvethatresultsfromunderexposure.Theshadowsarecompressedbadly.
0
ImageSteps
ExposureSteps
9.9Anunderexposure.Manyshadowtones,differentintheoriginalscene,arenowcompressed.
9.10Alighterprintfromtheunderexposedimage.Eventhoughtheoverallsceneislighter,shadowdetailhasnotbeenrestored.
pleasingdependsontheparticularsceneandtheopinionoftheviewer.Inthisscene,thehighlightsinthebuilding’sfacadearenowbetterdifferentiated.Ofcourse,noviewerwouldconsiderthatgainworththeincreasedcompressionoftheshadowweseehere.
Onceagain,wewilltrytocuretheproblem.We’velightenedFigure9.10inanattempttorecovertheshadowdetail.Aswemighthaveexpectedwhenlookingatthecharacteristiccurve,thelighterversiondoesnotrestoretheshadowdetail.Thisisbecausetheunderexposurehascompressedthosetonestoomuchforthemevertobesalvaged.
ARealSensor(CCDorCMOS)
Thepartofthecharacteristiccurverepresentingtheshadowstepsiscalledthetoeofthecurve.Thetoeofarealcharacteristiccurveislikelytobeonlyslightlystraighterthanthetoeofthebadcurve,soshadowcompressionisalmostasbadinarealimagesensor.
Thepartofthecharacteristiccurverepresentingthehighlightstepsistheshoulderofthecurve.Betweenthetoeandtheshoulderisthestraightline.Thestraightlineofarealcharacteristiccurveislongerthanthatofbaddigitalsensor(eitherCCDorCMOS).Therefore,theshoulderoccursathigherdensityrangesthantheimportanthighlightsinsomescenes.Highlightcompressionislessofaprobleminarealsensorthaninabadsensor.
Realfilmswerecompromisesbetweenourimaginaryidealonesandourimaginarybadones.Theflatteningofthecharacteristiccurveshoulderreducedhighlightdetailbutdidn'teliminateitentirely.Withinverywideranges,shortof,say,brightnessofathermonucleardetonation,thenegativehadatleastsomedifferentiationoftheverylightgrays.Withextrawork,aprintcouldbemadethatshowedthatdifferentiation,evenifitdidthatbadly!
Therealsensorhasanadditionaldisadvantagethatfilmdidn't.Thecurvesimplyendsatthetop.Photographerstendtoroutinelyoverexpose,whethershootingfilmorshootingdigitally;althoughitmaynotbeavirtue,it'sstillafact.Photographersshootingfilmdosobecauseit’s“safe.”Highlightlossiseasiertocompensatethanshadowloss.Photographersshootingdigitallydosotokeepasmuchiftheimageaspossibleoutofthe“noisy”lowerranges.Digitalphotographerscannotoverexposenearlyasmuch,however,becauseoftheabruptlossofdetailatthetopofthecurve.
USINGEVERYRESOURCE
Thedifficultiesofwhite-on-whiteandblack-on-blacksubjectsarenotcausedbyjustthesubjectsthemselves.Theproblemsarerelatedtotheverybasicsofthephotographicmedium:scenesgetrecordedonthoseportionsofthecharacteristiccurvethatpreservetheleastdetail.Thismeansthatnosingletechnique,orevengroupoftechniques,isalwaysadequatetodealwithsuchsubjects.
Whiteonwhiteandblackonblackrequirecompletecommandofalltypesofphotographictechniques.Thetwomostessentialsetsofthesetechniquesarelightingandexposurecontrol.Thesetwoworktogethertoproduceeachpicture.Therelativeimportanceofeachvariesfromonescenetoanother.Wesometimesthinkprimarilyaboutexposurecontrolandinothersituationsuselightingtechniquesastheprimarytool.Theremainderofthischapterdiscussesbothandsuggestsguidelinesaboutwhentousewhichtool.
WHITEONWHITE
Whitesubjectsonawhitebackgroundcanbebothpracticalandappealing.Inadvertising,suchsubjectsgivedesignersmaximumflexibilityinthecompositionofthepiece.Typecangoanywhere,evenoveranunimportantpartofthesubjectitself.Blacktypeonawhitebackgroundislikelytosurviveevenpoorreproductioninanewspaper.Furthermore,photographersdonothavetoworryasmuchaboutmakingthecropfittheavailablespace.Ifthepictureisreproducedtokeepthebackgroundpurewhite,readerscannotseeintheadwheretheedgeoftheprintmighthavebeenrelativetothesubject.
Somephotographersstillshootfilm,forverygoodreasons.Evenaftertechnologyrendersfilmtrulyobsolete,somephotographerswillprobablystill
shootfilmjusttobedifferent,likethosefewwhostillprinton19th-centuryemulsions.Youcanoverexposenegativefilmtobesafe,butweneedto
warnyouthatoverexposureincreasesgrain.
Thetwofactorsthatmostaffectgrainsizearethesensitivityofthefilmtolightandthedensityoftheimage.Weusuallychoosetheslowestfilmthat
allowsanacceptableapertureandshutterspeed.Afterthat,weminimizegrainbypayingattentiontodensity.
Thedensertheimageis,thecoarserthegrainsizeis.Itmakesverylittledifferencewhetheradensityincreaseiscausedbyanexposureincrease
oradevelopmentincrease.Theeffectonthegrainissimilar.
Thismeansthatthegrainisnotuniformthroughoutthescene.Thehighlightareahasmoregrainthantheshadowareabecauseofthedensity
difference.Thisfactsurprisessomephotographers,especiallythosewhosenegativesareconsistentenoughtoprintwithverylittlemanipulation.
Thedenserareasinmostnegativesproducelightgrayorwhiteintheprint.Thegrainiscoarseinthoseareas,butitistoolighttosee.Highlight
grainisalsoconcealedinaprintbyfurtherhighlightcompressioninherentinthecharacteristiccurveofthepaperitself.
Suppose,however,thatthehighlightdetailisnotadequatewithanormalprintingexposure.Dependingonthescene,mostphotographersremedy
theproblembyincreasingeitherthegeneralprintingexposureortheexposurejustintheproblemarea(a“burn”).Thismakessomeofthehighlight
stepsprintasiftheyweremiddlesteps.Printingthedensergraystepsasmiddlestepsrevealsthecoarsestgraininthenegative.
Highlightcompressioninthenegativeisnotasbadasshadowcompression,butthedefectiscompoundedbyincreasedgrain.Theresultingeffect
onimagequalitycanbeevenworse.
Formanyyears,goodphotographersrealizedthatblack-and-whitefilm,printedwithmodernenlargers,neededabout20%lessdevelopmentthan
thefilmdatasheetstoldthem,andtheygotmuchlessgrainwiththereduceddevelopment.Photographersshootingcolornegativefilm,however,
wereprettywellstuckwithstandardizeddevelopmenttimesbecausereducingdevelopmenthurtthecolorbadly.Thosephotographersowealotto
theformerpresidentoftheProfessionalPhotographersofAmerica,FrankCricchio,who,beforehestartedshootingdigitally,workedoutan
exposuresystemforcolornegativefilmthatguaranteedadequateexposurewithoutoverexposure.Heprovedhissystembymakingmuchlarger
printsthanotherphotographers,withbettersharpness.
Raw
ForatleastacenturyphotographersregrettedthatS-shapedcharacteristiccurveandwishedthefilmmakerscouldgetitstraight.Theysawtheloss
ofhighlightandshadowdetailinthosepartsofthecurveandrightlythoughtthatdetailcouldbeimprovedbyalinearcurve.Now,withdigital
photographyreplacingfilm,wehaveourwish,butitturnsoutthatithasitsownshortcomings.
TheRawfileformatofferedbydigitalcamerasstraightensthecurveandkeepsthehighlightandshadowdetailthatusedtobelostifwedonot
overexposeorunderexposethescene.Thetrouble,nowthatwecanactuallyseesuchapicture,isthatitlooksflat.Weliketoseemorecontrastin
themiddletonesandwe’rewillingtosacrificeabitofhighlightandshadowdetailtogetit.Soitappearswewillhavetokeepthosephotographic
defectsuntil,possibly,amajorandunlikelychangeinhumanpsychology.
TheadvantageofRawisthatwegettokeepthedetailuntilpostproductionandmakejudgmentsaboutwhatdetailweneedtosacrificetomakethe
picturelookright.Rawisoftencalled
“thedigitalnegative”becausephotographerscanmakesomeofthesamedecisionstheyusedtomakeinthedarkroom.Likeanegative,aRawfile
alsogivesthephotographerthefreedomtochangehisorhermind,tomorrowornextyear,andusetheRawfiletomakeanew,whollydifferentTIFF
orJPEGthanwhateverheorshefirstliked.
ThedisadvantageofRawisthateverycameramakerdefinesitdifferentlyandkeepsthatdefinitionasecret.ThispotentiallymakestheRawformat
hostagetothecameramakers’proprietarysoftware.That’sahugeproblem.YouorIcouldprintMatthewBrady’snegativestoday,maybebetter
thanhedid,butiftheRawsoftwaretointerprettoday’sdigitalfiledoesn’texistinanother150years,whatwillourdescendentsdowithourdigital
negatives?
It’sinterestingtogototheU.S.NationalArchivestolookatpicturesshotbyEdwardSteichenwhenhewasaNavyphotographerduringWorldWar
II.Thegovernmentownsthenegativesandgenerallymakesmuchworseprintsthanhedid.Butonceinawhileagovernmentlabtechnicianmakes
abetterprintthanhedid.Oldfilmcanrevealnewinformation.
SomefeelthatabettersolutiontoproprietaryRawisAdobe’sDigitalNegativeFormat(DNG).It’sanopen,nonsecretstandard,likelytosurvive
history’sforgetfulness.ItpreservestheadvantagesofRaw,butanyonewithsoftwaresavvy,includingthoseusingwhatevercomputerswe’llhavein
150years,canreaditandinterpretit.SomecameramakershavemadetheirRawformatscompatiblewithDNGbut,alas,toofew.
Unfortunately,white-on-whitesubjectsarealsoamongthemostdifficultofallscenestophotograph.A“normally”exposedwhite-on-whitesubjectisrecordedontheworstportionoftheusablecharacteristiccurve.Lessercontrastinthatportionofthecurvecausescompressionofthatpartofthegrayscale.Graystepsthatweredistinctlydifferentinthescenecanbecomesimilaroridenticalgraysinthephotograph.
Whitesubjectsonwhitebackgroundsalsolargelydepriveusoftheuseofoneofourfavoritelightingingredients:directreflection.Wehaveseeninearlierchaptersthatbalancingdirectanddiffusereflectioncanrevealdetailthatmightotherwisedisappear.Directreflectionisespeciallycontrollablebypolarizingfiltersonlightsourcesorlenses.
White-on-whitescenesgenerallyhaveasmuchdirectreflectionasanyotherscene,butthediffusereflectionisusuallybrightenoughtooverpowerthedirectreflection.Withsomuchcompetitionfromdiffusereflection,thecameracannotseemuchdirectreflection,andphotographersaccomplishlittlebytryingtomanipulateit.
However,wewillaccomplishevenlessbycontinuingtocomplainabouttheproblems.Sowewillgoontoadiscussionofhowtodealwiththem.
Goodlightingcontrolproducestonaldistinctionsinwhite-on-whitesubjects.Goodexposurecontrolpreservesthosedistinctions.Neithercontrolaloneisadequatetodothejob.Wewilldiscussboth.
ExposingWhite-on-WhiteScenes
Theextremelyhighandextremelylowestrangesofthecharacteristiccurvearethoseareaswherewearemostlikelytolosedetail.Reducingtheexposureofawhite-on-whitesceneputstheexposureinthemiddleofthecharacteristiccurve.Doingthismaymakethescenelooktoodark,butwecanfixitlater.Theworstthingthatcanhappenisthatwefixapicturesothatithasthesamelossitwouldhavehadwithanormalexposure,andthat’snottoobad.Theotherthingthatcanhappenisthatwefindwecangetmorehighlightdetail,andthat’saverygoodthing.Keepinmindthatthelossofshadowdetailthatcomesfromunderexposureofanormalsceneisnothingtofearherebecausetheshadowareaofawhite-on-whitesceneisprettylight.Howmuchcanwereduceexposurewithoutgettingintoothertrouble?
Followingaresomedefinitionswewillbeusing.Wewillconsideranormalexposuretobeareflectedlightreadingfroman18%graycardoranincidentlightreading.Wewillfurtherassumethatstandardreproductionrendersthatcardasexactly18%reflectanceintheprintedimage.Finally,wewillconsiderreducedexposureandincreasedexposuretobedeliberatedeviationfromthenormal.Thisdifferentiatesthemfromaccidentalunderexposureandoverexposure.
Atypicalwhitediffusereflectionisabout2%stopsbrighterthanan18%graycardseenunderthesamelight.Thismeansthatifwemeterawhitesubject,insteadofagraycard,weneedtoincreaseexposureby2%stopsmorethanthemeterindicatestogetanormalexposure.
Suppose,however,wefailtomakethat2%-stopcorrectionandexposeexactlyasthemetersuggests.Thismeansthatthesamewhitewillreproduceas18%graywithastandardprintingexposure.Thisismuchtoodark.Viewerswillalmostneveraccept18%grayas“white.”Suchanexposuredoeshaveitsadvantages,though:itplacesthewhitesubjectonthestraight-lineportionofthecharacteristiccurve.
However,weareundernoobligationtousestandardreproduction.Wecanreproducetheimageaslightasweneedsothattheresultingimageisanappropriatelylightgraythatviewerswillcall“white.”OncewemovetheimageupthetonalscaleandconvertitfromRawtoastandardfileformat,weget
theexpectedhighlightcompression.
Soifwe’regettingthehighlightcompressionanyway,whynotshootitnormallyandletthecompressionhappenfromthebeginning?Weshouldnotdosofortworeasons:(1)thereducedexposurereservesmorechoicesforlater,and(2)thedigitalsensordoesnothaveaperfectlylinearresponse;italsohasacharacteristiccurvewithashoulder,albeitslight.Reducedexposurekeepsthehard-to-holddetailawayfromthatshoulder.
Reducingtheexposureofwhite-on-whitesubjectsby2%stopsistheminimumexposureweareeverlikelytouse.Tryitforscenesthathavevery,verybrightwhites.Thewaytodothisistousetheexposureindicatedbyareflectionmeterandignoretheroutinecorrection.
Photographerswhohavethoroughlymasteredmeteringtechniquesmaybeoffendedbyoursuggestiontojustpointthemeterandread,thendowhatthemetersays,withoutanycalculationorcompensation.Theyoughttobe!Wewouldbecompletelyirresponsibletomakesucharecommendationifwedidnotgoontowarnyouaboutsecondaryblacksubjectsandtransparencies.
Usingtheuncorrectedexposureindicatedbythereflectionmeterworksfineifthesceneiscomposedentirelyoflightgrays.Ifanadditionalblacksubjectisinthescene,however,thatpartofthescenewilllackshadowdetail.
Whetherthislackofdetailisaproblemdependsentirelyonwhatthesubjectisinthespecificscene.Iftheblacksubjectisunimportantandifitistoosmalltoadvertisethedefect,thenthelackofshadowdetailwillnotbeobjectionable.
However,ifthesignificanceorthesizeofthesecondaryblacksubjectcommandstheviewer'sattention,thedefectwillalsobeapparent.Insuchacase,itwouldbebettertouseanormalexposureinsteadofareducedone.“Importance”isapsychologicaljudgment,notatechnicalone.Itisentirelyreasonabletodecidetoreducetheexposureforonewhite-on-whitescenebuttouseanormalexposureforanothertechnicallyidenticalscene.
Ifweconsiderthepossibleerrorsandacceptthereflectionmeterreadingofawhite-on-whitescenewithoutcompensation,thenthatisadeliberatedecisiontoreduceexposure.Ifweusetheexposurethatwereadonthemeterwithoutthinkingaboutthedangers,theresultmaybeaccidentalunderexposure.
Realizethatbeingfreetouselessexposureinawhite-on-whitescenealsoallowsusingaslowerISO.Decidingtoreduceexposureby2%stopsmeansthatwecanusethesameapertureandshutterspeedforISO32asthoseforanISO180exposednormally.
LightingWhite-on-WhiteScenes
Lightingawhite-on-whitescenerequiresenhancingbothtextureanddepth,likethelightingofanyotherscene.WecandothiswiththesametechniquesweusedinChapters4and5.Theotherspecialrequirementofwhite-on-whitescenesistokeepallpartsofthesubjectfromdisappearing!
Theeasiestwaytoobtainatrue“white-on-white”sceneistosimply“print”ablankpieceofpaper.Ofcourse,photographersdonotreallymean“whiteonwhite”whentheyusetheterm.Instead,they
mean“verylightgrayonverylightgray,withsomewhitesinthescene.”
Wehavetalkedaboutwhythesesimilarlighttonestendtobecomethesametoneinaphotograph.Goodexposurecontrolminimizesthisproblem.Butalightgraystilldisappearsagainstanidenticallightgray.Theonlywaytokeepsuchasubjectvisibleistomakeoneofthosegrayslighterordarker.Thisiswhatlightingdoes.
SubjectandBackground
Themostimportantgraystodistinguisharethoseofthesubjectanditsbackground.Withoutthisseparation,theviewercannotseetheshapeofthesubject.Aviewermaynevernoticethelossofminordetailwithinthesubject,butalostedgeisreadilyapparent.
Wecanlighteitherthebackgroundortheedgeofthesubjectsothatitreproducesaswhite(orverylightgray)inthephotograph.Oncewedecidewhichoftheseistobewhite,weknowthattheothermustbeatleastslightlydarker.Technically,itdoesnotmatterwhetherthemainsubjectorthebackgroundisslightlydarker.Eitherwaypreservestonaldistinction.
Psychologically,however,itmattersalotwhetherthebackgroundorthesubjectiswhite.Figure9.11showsawhitesubjectagainstawhitebackground.Wehavelitthescenetorenderthebackgroundwhiteandthesubjectlightgray.Whenyoulookatthepicture,yourbraininterpretsthesceneaswhiteonwhite.
However,thebrainislesswillingtoacceptagraybackgroundasawhiteone.LookatFigure9.12.Wehaverelitthescenetorenderthebackgroundlightgrayandthesubjectwhite.Younolongerseeawhite-on-whitescene;youseeawhite-on-grayone.
Figure9.12isnotabadpicture.Itstillhasgoodtonaldistinctionbetweenthesubjectandthebackground,anditispleasingineveryotherway.Youmaypreferthelighting,andwehavenoreasontodiscourageit.Wearesimplysayingthatitisnotagoodwhite-on-whiteexample.
Becausethissectionisaboutwhiteonwhite,wewillkeepthebackgroundwhite,ornearlyso,inallremainingexamples.Intheseexamples,thebackgroundneedstobebetween%stopand1stopbrighterthangraysintheedgesoftheprimarysubject.Ifitislessthan%stopbrighter,partofthesubjectmaydisappear;ifitismorethan1stopbrighter,flaremayscatterenoughlightinsidethecameratocostcontrastinthesubject.
9.11ThebackgroundlookswhiteandtheBachbustlookstobealightgray.Thebraininterpretssuchasceneaswhiteonwhite.
9.12Thebackgroundisnowalightgrayandthebustappearswhite.Thebrainnowinterpretsthevisualmessageaswhiteongrayratherthanwhiteonwhite.
9.13Onegoodlightingarrangementforawhite-on-whitesubject.
UsinganOpaqueWhiteBackground
Theeasiestwhite-on-whitesubjectsarethosethatallowseparatecontroloverthelightingoftheprimarysubjectanditsbackground.Inthosecases,wecanslightlyincreasethelightonthebackgroundtokeepitwhite.Puttingthesubjectdirectlyonawhiteopaquebackgroundisthemostdifficultwhite-on-whitearrangementbecausewhateverwedotoonealsoaffectstheother.Thisisalsothemostcommonarrangement,sowewilldealwithitfirst.Figure9.13illustratestheprocess.
LighttheSubjectfromAbove
Lightingfromaboveplacesthefrontofthesubjectslightlyinshadowbutfullyilluminatesthetabletop.Thisreadilyestablishesthegraysubjectandwhitebackgroundwewant.Inmostcases,thecameraseesgooddistinctionbetweenthesidesofthesubjectandthebackgroundwithoutanyfurtheradjustments.Figure9.14istheresult.
Notice,however,thatsuchanarrangementalsofullyilluminatesthetopofthesubject.Thelossoftonaldistinctioninthatareameanswehavetodosomemoreworkbeforeexposing.
9.14ThereisgooddifferentiationbetweensideedgesoftheBachbustandthebackground.However,thetopoftheheadhasvanished.
UseaGoboabovetheSubject
Thisstepisalmostalwaysnecessary.Weplacethegobotocastjustenoughshadowonthetopofthesubjecttobringitsbrightnessdowntoalevelsimilartothatofthefront.YoucanseetheimprovementinFigure9.15.
Youmayhavebeensurprisedthatwedidnotdiscussthesizeofthelightinthepreviousstep.Asfarasthesubjectisconcerned,youcanusealightofwhateversizethatlooksgood.However,werecommendamedium-sizedlightbecauseitislikelytoworkmosteffectivelywiththegobointhisstep.
9.15Agoboblockinglightfromthebust’sheadtakescareoftheproblemwesawinthepreviouspicture.Thetopoftheheadisnowclearlyvisible.
Thehardnessoftheshadowcastbythegoboisusuallymorecriticalthanthatofthesubject.Ifthelightistoosmall,wemaynotbeabletogettheshadowofthegobosoftenoughtoblendwiththerestofthescene.Alightthatistoolargemaykeepthatshadowtoosofttoeffectivelyshadethesubject.Usingamedium-sizedlightfromthebeginningreservestheprivilegeofexperimentingwiththegobolater.
Ifyouhavenotdonethisbefore,youmaynotknowhowlargethegoboshouldbeorhowfaritshouldbefromthesubject.Thesefactorsvarywiththesubject,sowecannotgiveyouformulas.Wecan,however,tellyouhowtodecideforyourself.Beginwithagoboaboutthesizeoftheoffendinghighlight.Foreaseofmovement,holditinyourhandwhileexperimenting.Youcanalterthesizeofthegoboandclampitappropriatelywhenyoufine-tunethesetuplater.
Thecloserthegoboistothesubject,thehardertheshadowofthegobobecomes.Movethegoboclosertothesubject,thenfartheraway,toseethishappen.Theedgeoftheshadowofthegoboneedstoblendnicelywiththeedgeofthehighlightweneedtoconceal.
Theshadowofthegobomaybecometoolightasyoumoveitfartherfromthesubject.Ifthishappens,tryalargergobo.Conversely,iftheshadowofthegoboblendswellbutistoodark,cutthegobosmaller.
Finally,whenthegobopositionisrightfortheprimarysubject,lookatitseffectonthebackground.Thegobowillalsocastashadowthere.Onmostsubjects,theshadowthegobocastsonthebackgroundwillblendnicelywiththatofthesubjectandwillnotbenoticeable.Thegoboshadowwillbesofteronthebackgroundthanonthetopofthesubjectbecausethebackgroundisfartherawayfromthegobo
thanthesubjectis.
Ifthesubjectistallenough,thegobomayproducenoperceptibleshadowonthebackgroundatall.Therewillbeaproblem,however,withveryshallowsubjects.Inanextremecase,suchasawhitebusinesscardonawhitetable,itisimpossibletoputashadowonthecardwithoutshadingthebackgroundequally.Inthosesituations,wemusteitheruseoneoftheotherbackgroundsdiscussedlaterinthischapterorresorttomaskingorretouchingafterthephotographiscompleted.
AddDimension
Thewhitebackgroundonwhichthesubjectsitswillprovideagreatdealoffilllight.Unfortunately,thisfillilluminationwillusuallybetooeventogivethepictureagoodsenseofdimension.Figure9.15istechnicallyacceptablebecausethesubjectisreasonablywelldefined,buttheblanduniformityofthegraysmakesitboring.
Ifthesubjectisverymuchdarkerthanthebackground,weneedtoaddareflectortooneside.Thisaddsbothfillanddimension.Moreoften,white-on-whitesubjectsareonlyslightlydarkerthanthebackground,andwedarenotfurtherbrightenthemwithfill.Instead,weusuallyaddablackcard,againtooneside.Thisblockssomeofthelightreflectingfromthebackgroundandproducesashadowedsidetothesubject.Figure9.16hasablackcardontheleft,justoutofcamerarange.
UsingaTranslucentWhiteBackground
Iftheshapeofthesubjectisveryflat,thereisnowaytoshadowitwithoutdoingthesametothebackgroundonwhichitsits.Onegoodsolutiontothisproblemistouseatranslucentbackgroundthatcanbelitfrombehind.Whiteacrylicisgoodforthispurpose.Aslongasthesubjectisreasonablyopaque,wecanlightthebackgroundtowhateverbrightnesswepleasewithoutaffectingthesubject.Figure9.17showsthelightingdiagram.
Figure9.18appliesthistechnique.Thesubjectiswelldifferentiatedfromthebackground.Notice,however,thattheilluminationunderthesubjecthaserasedanyhintofagroundshadow.
9.16Ablackcardontheleftreducedthefillreflectedfromthetabletop,creatingasenseofdepth.
9.17Atranslucentbackgroundphotographswhiterthanawhitesubject.
9.18Lightfromundertheflowereliminatedanyhintofagroundshadowintheprint.
Afterlookingatthispicture,wemightbeinclinedtoavoidthissetupanytimewewanttopreserveashadowunderthesubject.Shouldweavoidit?Absolutelynot.Oneofthesinglebiggestadvantagestothistechniqueisthatitallowsustocontroltheapparentshadowofthesubjectcompletelyindependentlyofthelightingofthesubject.Here'show.
Beginbyturningoffanylightsweintendtousetophotographthesubject.Next,setupatestlighttoproduceapleasingshadow.Itdoesn'tmatterwhetherthislightisgoodforthesubjectbecausewewillnotusethislighttoshootthepicture.Weintendtousethelighttotraceapattern(aswedidforthefamilyofanglesinChapter6andthereflectorbehindtheglassofliquidinChapter8).
9.19Manufacturingagroundshadow.
Next,slideanyopaqueorsemi-opaquepaperunderthesubject.(Ifyoumovethesubjectintheprocess,don’tworry.Criticalpositioningisunnecessaryatthistime.)Tracetheshadowpatternonthepaperwithapencil.Thenremovetheopaquepaperandcutouttheshadowpattern.Thefinalstepistogluetheshadowpatternunderthetranslucentbackground,asshowninFigure9.19.
Nowyoucanturnoffthetestlightandlightthesubjectinanymanneryouplease.Figure9.20isthefinishedpicture.Theshadowsundertheblossomandstemwerenotcastbythelightilluminatingthesubject.However,itcertainlylookslikeit.
UsingaMirrorBackground
Probablytheeasiest“white”backgroundtouseisamirror.Amirrorreflectsalmostnothingbutdirectreflections.Thesereflectionsarelikelytobemuchbrighterthanthediffusereflectionsfromawhitesubject.
Webeginthearrangementwithalightlargeenoughtofillthefamilyofanglesthatproducesdirectreflectionsontheentiremirrorsurface.(WedeterminewherethatfamilyisexactlyaswedidwiththeflatmetalinChapter6.Youcanlookbackatthatsectionifyouneedalightingdiagram.)Becausethelightsourcemustfillthefamilyofanglesdefinedbytheentirebackground,thismayturnouttobethelargestlightwewilleverneedforaflatsubject.
9.20Agobowasplacedunderthetabletoproduceashadowthatlooksasthoughitwascastbytheflower.
Theotherspecialrequirementforthelightsourceisthatitshownodistractingtexture.Rememberthatthelightitselfwillbevisiblyandsharplyreflectedinthemirror.
NoadditionalstepswereneededtoproduceFigure9.21.Alightsolargeusuallyproducesshadowssosoftthatnootherlightisrequiredforfill.Furthermore,thisisoneofthefewtechniquesinwhichthebackgroundcanreflectmuchfilllightunderthesubject.
Anoccasionaldrawbacktothistechniqueisthereflectionofthesubject.Itmaybeconfusing,dependingonthecropandontheshapeofthesubject.Ifthesubjectisappropriate,trymistingthetabletopwithwatertocamouflageandbreakupthatreflection.
9.21Amirrorreflectingthelightsourceisanotherbackgroundthatis“whiter”thanthe“white”flower.
Theotherpossiblecomplaintisthelackofgroundshadow.Thereisnowaytoobtainonewiththissetup.Ifyoufeeltheshadowisnecessaryforyoursubject,thensomeotherarrangementwillbebetter.
InAnyCase,KeeptheBackgroundSmall
Wehaveexplainedwhydirectreflectionsareusuallynotveryimportanttowhitesubjects.Thefewweseegenerallyaddabitofdimension,butcomparedwiththediffusereflections,theytendtobetooweaktobemajorplayersinthelightingevent.
Theexceptiontothisisdirectreflectionontheedgeofthesubject.Directreflectioninthoseareasisespeciallylikelytomakethesubjectdisappearagainstthewhitebackground.Tomakemattersworse,thewhitebackgroundsinallofthesearrangementsareinexactlythepositionmostlikelytocausethesereflections.
Themostcommonsolutionisthesameasthetechniqueforkeepingreflectionofftheedgeoftheglassinthebright-fieldmethod,asdiscussedinChapter7:keepthebackgroundassmallaspossible.Sometimesourbackgroundismuchlargerthantheareathecamerasees,andwedonotwanttocutit.Inthosesituations,weeitherconfinethelighttotheimageareaorsurroundtheimageareawithblackcards.
Anotherdangerofwhite-on-whitesituationsiscameraflare.Largewhitebackgroundsscatteralotoflightinsidethecamera.Thisflarewillprobablybesouniformthatyouwillnotseeit,evenwhenthegenerallossofcontrastissignificant.However,ifyoustayinthehabitofkeepingthewhitebackgroundonlyaslargeasitneedstobe,youwillnotneedtoworryabouttheflare.
BLACKONBLACK
Masteringwhiteonwhiteisagoodstepforwardintheprocessofmasteringblackonblack.Manyoftheprinciplesaresimilarbutappliedinreverse.Wewillpointoutsomeofthesesimilarities,butwewillemphasizethedifferences.
Themajordifferenceinexposureconsiderationsisnotrecordinginthecamera'snoiserange.Themajordifferenceinlightingconsiderationsistheincreasedvisibilityofdirectreflection.
ExposingBlack-on-BlackScenes
Thesectiononthecharacteristiccurvepointedoutthecompressionofgraystepsinboththeshadowandthehighlightsteps.ThishappenswheneverweshootaJPEG,andithappenswheneverweconvertanimagefromRawtoanyotherconventionalformat.Wealsosawwhyoverexposureexaggeratesthisprobleminwhite-on-whitescenesandwhyunderexposureexaggeratesitinblack-on-blackscenes.
Theproblemissomewhatworseintheshadowstepsasaresultofdigitalnoise.Theserandom,minutespecklesmaybeunnoticeableinanormalscenewithnolargedarkareasbutapparentinblackonblack.Theseverityoftheproblemdependsonthequalityofthecamera,butfornowatleastweseeittosomeextentinallcameras.Soweincreasetheexposureofablack-on-blackscenetomoveitclosertothemiddlegrays,evenifweknowwe'regoingtodarkenitbackdownlaterinpostproduction.
Themostextremeamountthatwemightusetomodifytheexposureissimilartowhiteonwhite,2%stops,exceptthat,becauseofnoise,we'remorelikelytoactuallygotothatextremehere.Thismeansweexposethatmuchmorethanwhatagraycardreflectionreadingoranincidentreadingtellsus.Orwecanaccomplishaboutthesamethingbysimply
pointingareflectionmeteratthesubjectandexposingasitsays,withoutanycompensation.
Thisisasatisfactoryshortcuttomoresophisticatedmeteringtechniquesifwerememberthepotentialproblemsitcancreate.These,too,aresimilartothoseforwhite-on-whitesubjects.
Thismethodwill,ofcourse,overexposeanysecondarylight-graysubjectsinthesamescene.Therefore,it’sapplicableonlywhenthescenetrulyapproximatesblackonblack.
LightingBlack-on-BlackScenes
Black-on-blackscenesrequirespecialattentiontoexposuretorecordasmuchdetailaspossible.However,increasingtheexposureofablack-on-blacksceneworksonlyiftherearenosecondarywhitesubjectsindangerofoverexposure.
Evenwithoutanywhitesubjects,increasedexposureofablack-on-blackscenesometimesdoesnot
lookright,evenifitrecordsmoredetailthananormalexposure.Althoughgoodexposureisessential,itisnotenough.Themanipulationofexposureandlightinghelpsoneanothertorecordthescenewell.Nowwewilllookatthelightingprinciplesandtechniques.
Like“whiteonwhite,”“blackonblack”isanaccuratedescriptionofasceneonlywhenweacknowledgeittobeanabbreviationforalongerdescription.Abetterdescriptionwouldbe“ascenecomposedmostlyofdarkgraysbutwithsomeblacksinitalso.”
Likeallscenes,lightingblack-on-blackscenesrequiresthatwerevealdepth,shape,andtexture.Justaswithwhite-on-whitescenes,thelightingofblack-on-blackscenesneedstomovesomeoftheexposurestepsinthescenetothemiddleofthedensityscale.Thisishowweovercomethetendencyforverylightorverydarksimilartonestobecomeidenticalinaphotograph.
White-on-whitescenesproduceagreatdealofdiffusereflection;thisiswhatmakesthemwhite.Conversely,blacksubjectsareblackbecauseoftheirlackofdiffusereflection.Thisdifferenceindiffusereflectionisimportantmainlybecauseofwhatitimpliesaboutdirectreflection.
Thegreatestsingledifferencebetweenlightingblack-on-blackandwhite-on-whitescenesisthatmostblack-on-blackscenesallowusthefulluseofdirectreflection.Whitesubjectsdonotnecessarilyproducelessdirectreflection.Instead,whateverdirectreflectionawhitethingdoesproduceislessnoticeablebecausethediffusereflectionissomuchbrighterbycomparison.Bythesametoken,blackthingsdonotproduceanymoredirectreflection.However,thedirectreflectiontheydoproduce
ismorevisiblebecausethosereflectionshavelesscompetitionfromdiffusereflections.
Thus,theruleofthumbforlightingmostblack-on-blackscenesistocapitalizeondirectreflectionwheneverpossible.Ifyouhavemasteredlightingmetal,youknowthatweusuallydothesameforthosecases.(Directreflectionmakesthemetalbright.Werarelywanttophotographittoappeardark.)Therefore,anothergoodruleforblackonblackistolightitasifitweremetal,regardlessoftheactualmaterial.
Generally,thismeansfindingthefamilyofanglesthatproducesdirectreflectionandfillingthatfamilyofangleswithalightsourceorsources.(Chapter6describeshowtodothis.)Wewilltalkaboutspecificsduringtheremainderofthischapter.
SubjectandBackground
Wecanonlyphotographascenecomposedofgrays,notatrulyblack-on-blackone.Thismeansthateitherthesubjectorthebackgroundneedstobedarkgray,notblack,tokeepthesubjectfromdisappearing.
Figure9.22isablacksubjectonablackbackground.Noticethatwehavelititsothatthebackgroundisabsolutelyblack.Doingthismeantthatwealsohadtokeepthesubjectfrombeingabsoluteblack.Renderingthesubjectasadarkormiddlegraykeepsitdistinctfromthebackgroundandpreservesitsshape.
Ablacksubjectonadarkgraybackgroundcouldmaintainthesamedistinction.Ineithercase,thereis
enoughdifferencebetweenthesubjectandthebackgroundtokeepthesubjectfromdisappearing.However,illuminatingthebackgroundcausesadditionalproblems.Figure9.23showsthem.
Thebackgroundnolongerlooksblack.Wearepsychologicallywillingtoacceptadarkgraysubjectasblack,butwecannotacceptadarkgraybackgroundasblack.Thisisalmostalwaystrueforsimplescenesthatdonotgivethebrainmanyothercluestodecidehowtheoriginalscenelooked.Thesameisalsotrueformanycomplexscenes.
Thiscorrelateswiththeearlierprinciplethathumanbrainsconsidermostscenestobewhiteonwhiteonlywhenthebackgroundispure,ornearlypure,white.Italsosuggestssimilaraction.Ifyoujustwanttodifferentiatethesubjectfromthebackground,keepeitheroneofthemblackandmaketheotheronegray.However,ifyouwanttosuccessfullyrepresent“blackonblack,”makesurethebackgroundisasblackaspossible.
9.22Thebraininterpretsagraysubject,suchasthispot,againstablackbackgroundasablack-on-blackscene.
9.23Thesubjectisblack,andthebackgroundisdarkgray.Thebrainnolongeracceptsthesceneasblackonblack.
Youwillseethatthisopinioninfluencesalmosteverytechniquewearegoingtosuggest.Thereisonlyoneexception,andwewilltalkaboutthatnext.
UsinganOpaqueBlackBackground
Puttingablacksubjectonanopaqueblackbackgroundisusuallyoneoftheworstwaysofcreatingablack-on-blackscene.Wediscussitfirstbecauseitisoftenthemostavailablesolution.Moststudiophotographershaveblackseamlesspaperhandy.
Figure9.24showstheproblem.(ThelightingisalargeoverheadsourcelikethatusedforaboxinChapter5.)Thepaperbackgrounddirectlyunderthesubjectreceivesasmuchilluminationasthesubjectitself.Thereisnoeasywaytolightthesubjectanybrighterthanthebackground.Weknowthatweneedtorenderthesubjectdarkgray,notblack,topreservedetail.However,ifthesubjectisnotblack,thenthebackgroundunderitcannotbeblackeither.
Wecoulduseaspotlighttoconcentratethelightontheprimarysubject,thuskeepingthebackgrounddarker.Remember,however,wewanttoproduceasmuchdirectreflectiononthesubjectaspossible.Thisrequiresalargelightsourcetofillthefamilyofanglesthatdoesthat.Usinglargelightsgenerallymeansusingnospotlights.
9.24Theblackpapercannotbeexposeddarkenoughtorenderitblackiftheflashlightisproperlyexposed.
Wecouldalsohopethatalotofthereflectionfromthebackgroundispolarizeddirectreflection.Thenwecoulduseapolarizingfilteronthecameralenstoblockthatreflectionandkeepthebackgroundblack.Sometimesthisworks,butinmostofthosescenesthedirectreflectionfromthesubjectisalsopolarized.Unfortunately,thepolarizerislikelytodarkenthesubjectatleastasmuchasitdarkensthebackground.
Thebestsolutionistofindabackgroundmaterialthatproduceslessdiffusereflectionthanthesubject.Blackvelvetservesthispurposeformostsubjects.Figure9.25istheearliersubjectphotographedwiththesamelightingandthesameexposurebutwithblackvelvetreplacingthepaper.
Therearetwopossibleproblemstotheblackvelvetsolution.Afewsubjectsaresoblackthateventhevelvetwillnotbeblackerthantheyare.Amorecommonproblemisthattheedgesoftheblacksubjectmergewiththeirownshadow,andweseesomeofthatinthispicture.Whetherthelossisacceptableisajudgmentcallandwilldifferfromonepicturetoanother,butwe’llassumeit’sunacceptableherebecausewewanttotalkabouthowtodealwithit.Filllightdoesnothelpmuch.Rememberthatthesubjectdoesnotproducesignificantdiffusereflection,andtheonlyplacefromwhichalightcanproducedirectreflectionontheedgesofthesubjectislocatedwithintheimagearea.
9.25Withthesameexposure,theblackvelvetismuchdarkerthantheblackpaperusedinFigure9.24.
NoticethatthisproblemissimilartotheonepresentedbythemetalboxshowninChapter6.Wesolvedthatproblemwithinvisiblelight.Unfortunately,wecannotreflectverymuchlight,invisibleornot,fromblackvelvet.Thatrequiresaglossysurface.
UsingaGlossyBlackSurface
InFigure9.26wesubstitutedablackacrylicsurfacefortheblackvelvet.Thenwebouncedalittleinvisiblelightfromtheglossysurfacetofillinthesidesofthesubject.Thisworksforalmostanyblacksubject.Ordoesit?Noticethatthelargelightabovethesubjectalsofillsthefamilyofanglesthatproducesdirectreflectionontheglossyacrylic.Therefore,thebackgroundisnolongerblack.Becauseyousawthatsoquickly,youprobablyalsorememberthatwesaidearlierthatthebackgroundhadtostayblack.
Wewouldliketotalkourwayoutofthisapparentdiscrepancybypointingoutthatthebrainneedstoseeablackbackgroundinsimpleblack-on-blackscenes.Thesubject,background,andreflectionofthesubjectadduptoamorecomplexscene.Wemaintainthattheblackreflectionunderthesubjectisasufficientvisualcluetotellthebrainthatthesurfaceisblackbutglossyandreflectinglight.Sothisisstillablack-on-blackscene!
9.26Ablackacrylicbackground.Noticethesharplyoutlinedreflectionoftheflashlight.Isthesceneblackonblack?
Thisargumentoughttoconvincemostreaderstoletusgetbywiththegraybackground,butafewofyouwillbelesscharitableandinsistthatwekeepouroriginalcommitment.Wewilldosowiththenextsolution.
KeeptheSubjectawayfromtheBackground
Supposeweplacethesubjectfarenoughfromthebackgroundthatthelightingofthesubjecthasnoeffectonthebackground.Wecanthenlightthesubjectanywaywepleaseandthebackgroundwillremainblack.
Thisiseasyifwecropthebottomofthesubjectoutofthepicture.InFigure9.27themodelhandisonapedestalseveralfeetfromthebackground.Thisallowsustolightthehandwellwithalmostnolightonthebackground.However,iftheentiresubjecthastoshow,wehavetosupportitwithtrickery.
Amateursassumeprofessionalphotographersdothiswithstring.Sometimeswedo,buttoooftenthestringneedstoberetouched.
9.27Thesubjectisseveralfeetfromthebackground.Thismakesiteasytolightwithoutlightfallingonthebackground.
(Stringmightoccasionallyescapeundetectedinabriefmotionpictureorvideoshot,butitislikelytobeapparentinahigh-qualitystill.)Retouchingablackbackgroundisusuallynotdifficult.However,doingnoretouchingatallisevenbetter,sowewillsuggestsomeotherways.
InChapter6weinvisiblysupportedthemetalboxonasheetofglass.Thenwehadtouseapolarizingfiltertoremovethepolarizeddirectreflectionfromtheglasssurface.Thisdidnotaffectthemetalbecausedirectreflectionfrommetalisrarelypolarized.
Theglasstablewillnotworkformostblacksubjects.Muchofthedirectreflectionfromablacksubjectislikelytobepolarized.Ifweuseapolarizingfiltertotakethereflectionoffourtablesurface,wewillprobablyturnthesubjectblacktoo.
THEHISTOGRAM
Achapteronblackonblackandwhiteonwhiterequiresmoretalkaboutthetechnologyofphotographythananyother.Thismakesitagoodplacetotalkaboutthehistogram.Wewillclosewiththat.
ManyphotographersfirstencounteredthehistograminAdobePhotoshop(Image>Adjust>Levelsgetsyouthere).Afterlearningtousehistograms,manyofusdecidedthiswasamuchmorestraightforward
methodofimagecontrolthananytechnologyintraditionalphotography.Nowmanydigitalcamerashavebroughtthehistogramintotraditionalphotography.(Isadigitalcameratraditionalphotography?Wemaintainthatitcertainlycanbe.)
ManycamerasdisplayahistogramofthesceneweareabouttoshootandallowustomakePhotoshop-likecorrectionsbeforeweshoot.NoneofthedigitalcameramakershasyetimplementedthehistogramaselegantlyasAdobe,butpresumablytheywillgetthere.
Conceptuallyspeaking,histogramsaresimpleenough.Theyarenothingmorethangraphs—andquitesimpleonesatthat.However,onceyoulearnhowtointerpretthem—howtodecodetheinformationtheycontain—histogramsbecomeextraordinarilyusefultools.Thetruthisthatintoday'sdigitalworld,anunderstandingofhistogramsissoimportantnophotographercanaffordtobewithoutit.
Ahistogramismadeupoflines.Eachlinerepresentsthenumberofpixelstheimagecontainsforeachofthe256valuesthatconstitutethegraytonalscalefromtheblackestblacktothewhitestwhite.
Ifweareshootingcolor,usuallythecasewhenweareshootingdigitally,thebasichistogramisacompositeofthreehistograms:oneeachforred,green,andblue.Ifweneedtomakecoloradjustments,wecanselectthehistogramforasinglecolorandmanipulateitalone.
Fornow,however,wewillignorethatandassumeweareshootingablack-and-whitephotographaswedoinmostoftherestofthisbook.It’sjustsimplertotalkaboutandsimplertounderstandthatway.
LookatFigure9.28.Itisatypicalhistogram,anditrepresentsinformationaboutthephotographwesawearlierinFigure9.27.Putanotherway,wecansaythatFigure9.28isagraphshowingthenumberofpixelsateachofthemanydifferentbrightnesslevelsthatmakeupFigure9.27.
They-axisatthefarleftofthegraphshowsthenumberofpixels,andthex-axisalongthebottomshowstheirbrightness,orwheretheyfitintothepicture’soveralltonalrange.Thedarkestpixelsareonthehistogram’sleftside.Thelightestareontheright,andthemiddle-graytonesareinthemiddle.Whenweputallthispixelinformationtogether,weendupwithagraphthatshowsuswhattonalvaluesarepresentinapictureandhowtheyaredistributedthroughoutit.
Totranslatethisintothelanguageofgrayscalevalues,wecansaythattheblackestofblacksatthehistogram’sfarlefthasatonalvalueof0.Thewhitestofwhiteshasatonalvalueof255,andthemiddlegrayhasatonalvalueof128.ForthosefamiliarwiththeZonesystem,thefarleftofahistogramcorrespondstothe“0”Zone.ThemiddlegraycorrespondstoZoneV,andthefarrightcorrespondstoZoneX.
9.28Thehistogramshowshowmuchofeachgrayscaleorcolorvalueexistsinthescene.
Earlierwetoldyoutherewere256shadesofgrayfromblacktowhite.Nowwetellyouthehighestnumberonthescaleisonly255.Thisisnotatypo:thezerocountsasacoloralso.
Becausethisisahistogramofablack-on-blackscene,itshowsnowhiteorlightgrays.Noticethatthelightestpixelinthesceneisabout218or220,not255.Similarly,awhite-on-whitescenewouldhaveveryfewpixelsattheleftsideofthegraph.
PreventingProblems
Wecanalsolookatthishistogramandtellthatthepicturehasprobablybeenmanipulated.Lookatthegapsinthehistogramatbrightnesslevelsofabout93,110,and124andinfourotherplaces.Suchgapsarerareinsceneswephotographandtheyusuallyindicatedatalostthroughsubsequentmanipulation.Inthiscase,thelossisminor.Overmanipulation,however,canleadtosevereproblems.
SupposewehaddecidedthatFigure9.27wastoodarkandthenlightenedit.Figure9.29istheresultandFigure9.30isitshistogram.
9.29ThesamephotographwesawinFigure9.27,nowsubstantiallylighter.
9.30ThehistogramforFigure9.31.
Thenewhistogramhasapproximately100gaps.Thisisexactlywhyhistogramsaresouseful.Byglancingatahistogram,fairlyinexperiencedphotographerscanseeproblemstheymightotherwiseoverlookandeventhemostexperiencedeyesgetreassurance.EvenifwedecidethatFigure9.29isagoodpicture,itshistogramshouldcauseustoworry.
Overmanipulation
Manyaspectsofmanipulatingthehistogramareidenticalinthecameraandinpostproduction,butthedifferencesbetweenthetwoareimportant.Althoughpostproductionhasnothingtodowithlighting,wewouldberemissintellingyouasmuchaswedohereandthenleavingyoutothinkwehavetoldthewholestory.Wehaven’t.There’smore,andit’ssoimportantweoughttomentionitevenifitdoesn’tdirectlyrelatetolighting.
Thebestwaytoavoida“bad”histogramistolightthescenecorrectlyandexposethepicturecorrectlyinthefirstplace.Sometimesthisisimpossible.Wecan’taskarapidlyevolvingnewseventtowaitforustosetuplights!
Overmanipulationisoftencausedbyrepeatedadjustmentstotheimage:weadjusttheimage,lookataproof,tweakabitmore,thenrunanotherproof.Pleasedon’tdothis!
Intoday'sdigitalworld,imagesoftenmovearoundfromplacetoplaceandpersontoperson.Ateachstepalongtheway,theircolorrange,saturation,hue,andalltheotherparametersmayshiftandchange.
Itisnotunusualthatsuch“refining”producesanimagethatishopelesslyovermanipulated.Unfortunately,however,thisconditionmaynotbeimmediatelyobviouswhenwelookatthepictureonalmostanyexistingmonitor.Fortunately,however,itshistogramwillwarnusataglance.
Whenweadjustahistogram,wespreadcertaingrayscalevaluesoveralargerrange.(That'swhatcausesthosegapsinthe“bad”histogram.)However,thetonalscaleislimited,andwhenweexpandpartoftherangeweoftencompressanotherpart.Compressionmeansthatgrayscalevaluesoncerepresentedasawiderangenowoccupyanarrowerrange.Thismeansthattwovaluesthatwereoriginallydifferentgraysnowbecomethesamegray.Detailislost.Isthisallright?Veryoften,yes,ifthesacrificeismorethancompensatedforbyimprovementsinotherpartsoftheimage.
Themoreseriousproblemcomesfromrepeatedadjustment.Thelossiscumulative,andifithappensinsmallsteps,youmaynotevennoticeit.
Thesolutionistokeeptheoriginalfile,tomakeadjustmentstoacopy,andtokeepnotesaboutwhattheadjustmentswere.Thenifwearenothappywiththeresult,deletethealteredfileandreturntotheoriginaltoreadjustbasedonournotes.RecentversionsofPhotoshopallowkeepingsuchnotesinthefileitself.
AnotheralternativeistouseaPhotoshopadjustmentlayer.Thisway,noadjustmentismadetotheoriginal;instead,theadjustmentlayerrepresentstheimageonthemonitororinaprintoutasiftheadjustmentshadbeenmade.Thereis,therefore,noharminreturningtotheadjustmentlayerandreadjustingasmanytimesasweplease.
CURVES
Becausethedigitalrealmforcesustotalkaboutissuesthatdonotstrictlyrelatetolighting,weshouldalsomentioncurves.Wewillnotgivedetailedinformationherebecauseexistingdigitalcamerasdisplayonlyhistograms.(Somecamerasmaydisplaycurves,however,bythetimeyoureadthis.)Curvesareapostproductiontoolthatonthemonitorlookverymuchlikethefilmcharacteristiccurves
wesawearlierinthischapter.Theylookquitedifferentfromthehistogrambutrepresentmuchthesameinformation(Figure9.31).Theirusediffersfromthatofthehistogramintwoways:(1)theydonottellushowmuchof
9.31TheCurvesdialogbox.
eachvalueisinthescene,and(2)whereasthehistogramallowsustoadjustthreepointsonthescale(black,white,andthemidpoint),curvesallowustosetandadjustasmanypointsasweplease.
Theabilitytocorrectmultiplepointsinthescalemakescurvesamuchmorepowerfultoolforcorrectingapictureandforruiningit.Asitdoesforlevels,Photoshopallowsmakingcurvesadjustmentsinanondestructivelayer.
Weencouragebeginnerphotographerstolearntocontrolthehistogramfirstandthen,later,tomoveontocurvesandusethosenondestructiveadjustmentlayers.
NEWPRINCIPLES
Wehaveintroducedveryfewnewprinciplesinthischapter.Instead,wehavetalkedmostlyaboutbasicphotographyandbasiclighting(plusafewbitsofmagicandchicanery).
White-on-whiteandblack-on-blacksubjectsdonotrequiremanyspecialtechniques.Thesesubjectsdo,however,requirethebasics,appliedmeticulously.Thismaybetrueofphotographyingeneral.
Professionaldevelopmentmaynotbesomuchamatteroflearningnewthingsbutoflearningand
relearningthebasicsandcombiningtheminmoreperceptiveways.
Oneofthesebasicsisthatlightbehaveslikelight,andnoneofourpietyorwitcanevermakeitdootherwise.Weliketosaywecontrollight,butoftenallwecanreallydoistocooperatewithwhatitwantstodo.Thisistrueofanylight,inthestudiooroutofit.
Youwillhearmoreofthisinthenextchapter.
10
TravelingLight
Locationlightingpresentsallsortsofchallenges.Somearerelativelyeasytosolve.Othersrequireagoodbitmoreeffort.Somerequireyoutomovehundredsofpoundsofgeararound,whereasotherscanbetakencareofbythecleveruseofaportableflashweighinglessthanapound.Inthefollowingpageswepresentanumberofapproachesthatwehavefoundhelpful.
SOMEVERYGOODNEWS
Duringtheyearssincethefirsteditionofthisbookwaspublished,photographyhasexperiencedanamazingrevolution—thedigitalrevolution.Ithasturnedtheworldofimagemakingonitshead.Beitinvolvingcameras,lights,orpostproduction—theartandscienceoffreezingamomentintimehavechangedtosuchadegreethattheywouldbealmostunrecognizabletophotographersplyingtheirtradeanamazinglyfewyearsago.
Andthisisalmostallgoodnews—very,verygoodnewsasweseeit.Thisisbecausethenewworldofphotographyletsmorefolksinandallowsthemtoenjoyevermoresophisticatedmodesandmannersofpicturemaking.
Andofallthemanyassortedvenuesforpicturemaking,nonehasbenefitedmorethanlocationshooting—particularlythelightingsideofit.Thereasonforthisissimple:Picturemakinghasgonedigital!
Thesimpletruthisthatthefantasticlittleexternalor“hotshoe”flashesthatareattheheartofthelightingtechniquesfavoredbysomanyoftoday’stopprofessionalsareactuallyminicomputersconnectedtoflashtubes.Butthat’snotall.Today’scomputer-centricflashgearismarried.Itismarriedtothecomputer-lenscombinationsthataretoday’severadvancingdigitalcameras.
Fortunatelyforus,theirsisanextraordinaryunion.Today’slight-givingandpicture-recordingcomputer-drivenunitsareinconstantelectroniccommunication—communicationthat,onceweusersunderstandit,iscapableof,andoftendoes,produceamazingresults.
Withtheaboveinmind,letusmoveontoabriefaboutchoosingthelightsthatarebestforwhatyouwanttodo.
CHOOSINGTHERIGHTLIGHT
Threebasickindsofstrobes,or“flash,”areavailabletoday.Theyrangefromthebig,heavyandhugelypowerfultotheverysmallandlight,butstillamazinglypowerful.
Inmyownshooting,Iusuallyuseoneortheotherofthese.However,itisnotuncommonforphotographerstocombinethem.Forexample,oneaccomplishedhusbandandwifeweddingteamIknowfrequentlyusesamedium-weightbatterypackportablestrobemountedonastandandaimedattheceilingandacamera-mountedhotshoeflashtogether.Thesetwolightsareconnectedbyawirelesscommandsystem.Wheneverapictureistaken,bothlightsfiresimultaneously.
StudioStrobes
Attheheavy—frequentlyveryheavy—endofthegamutarethestudiostrobes.Butjustbecausetheyhavethewordstudiointheirnamedoesnotmeanthattheyaredestinedtoalwaysstayinthatenvironment.
When,forexample,youarecalledupontoshootthe25membersofaboardofdirectorssittingaroundanenormousconferencetable,allindarksuitsandsurroundedbydarkpaneling,youneedplentyoflight.Studiostrobescanprovideenoughwatt-seconds,usually1200to4800watt-secondsperpowersupply,tomeetsuchlarge-scale,high-qualitydemands.
Ofcourse,thereisnodenyingthatstudiostrobesarecumbersometoworkwithonlocation.Andtheyareevenmoresoifthelocationlackselectricalpowerandyouhavetolugagenerator,numerousheavy-dutyindustrialextensioncords,plug-inboards,stands,andothersuchaccessorieswithyou.Duringsuchshootsitiseasytobecomelostinwonderaboutwhyoneeverthoughtitwouldbegreatfuntobecomeaphotographer.
PortableStrobes
Nextdowntheportabilityscalearetheheavy-dutyportablestrobes.Batterypowered,thesearelesspowerfulthantheirstudiocounterparts.Theyare,however,considerablyeasiertocarryaround.Averaging
from100to1200watt-seconds,thelowerwattagetypepowerpacksofsuchstrobesaresupportedbyshoulderstrapsandattachedtotheflashheadbyapowercord.Thehigherwattagetypesareplacedonthegroundandconnectedtoaflashheadonastand.
LightweightHotShoeStrobes
Lightweightandpowerful,today’sadvancedhotshoestrobesofferahighdegreeofportabilityandmorethanenoughlightformanysubjects.Notonlycantheseunitsbeusedoncamera(hencethecommonname,hotshoe)theycanalsobefiredoffcamera.
Inaddition,theseunitscanbecombinedintomultipleflash“gangs”andfiredbybothradioandinfraredwirelesscontrolsystems.And,makingthemevenmoreuseful,thereisalargearrayofdiffusersandothersuchaccessoriesavailableforthem.
Becauseofalloftheabove,theseflasheshavebecomethelightsofchoiceformanyoftoday’stop-flightshooters—particularlythosewhospendmuchoftheirlivesontheroadshuttlingbetweenlocations.
GETTINGTHEEXPOSURERIGHT
Studiophotographersoftenworkundersuchconsistentconditionsthattheycanusethesameexposuretheydidthedaybeforewithoutthinkingaboutit.Determiningexposureismoredifficultonlocation.Ambientlightvaries.Thebrightnessofreflectivewallsandceilingsdiffersfromonelocationtoanother.Thedistancetothosereflectivesurfacesdependsonthesizeoftheroom.
Therearethreebasicwaysofcomingupwiththerightexposureusingstrobes:letthestrobedothework,useaflashmeter,orcalculate.Inthiseditionwehavedecidedtoconcentrateonthefirsttwoandleavethethirdout.Wecametothisdecisionfortworeasons.First,today’sdigitalcamerasarethemastersofinstantgratification.Amomentafteryoupressyourshutterrelease,theresultisstaringupatyoufromyourcamera’sLCD.Thatletsyouseehowthingsaregoingwhileyouareshooting.If,forexample,yourshotisonthedarkside,youknowitimmediatelyandlightenitthenandthere.Second,today’sthrough-the-lensmeteringsystemsareamazinglyaccurate.Theyalmostalwaysproduceflashresultsthatareatleastacceptable.Withafewtestshots,itisthenrelativelyeasytoarriveatexactlytheexposureyouwant.
If,however,youareinterestedinlearningthecalculationsbehindtheexposuredecisionsmadebytoday’sadvancedflashunits,yougototheirinstructionmanuals.Theyprovidedetailedinformationonhowtocalculateflashexposurewiththeirparticulargear.
LettingtheStrobeDeterminetheExposure
Today'shotshoestrobesreadthelightreflectedfromthesubject,andthenquicklyturnoffwhentheythinktheyhaveseenenoughlighttoexposethesceneproperly.Severalofthemajormanufacturersofferautomaticstrobesspecificallydesignedforusewiththeircameras.Thesededicatedunitsmaximizetheabilityofthecameraandstrobetoworktogether.
Oneofthemostimportantfeaturesthatdedicatedstrobesofferistheoptiontousethrough-the-lensmetering.Inadditiontoeaseandspeedofoperation,thechiefadvantageofsuchstrobesisthattheyaccountfortheenvironmentwhereyouareshooting.If,forexample,youuseoneinalargegymnasiumandthentakeitintothecoaches'office,itwillmaketheproperexposureadjustmenttocompensateforthestrobelightreflectedfromthewallsofthesmallerroom.
UsingaFlashMeter
Anumberofdifferentflashmetersareavailable.Althoughthedetailsoftheiroperationvarysomewhat,theyallcalculatetheproperapertureatwhichthelensshouldbesetforanygivencombinationofambientlightandflash.
Weuseflashmetersfromtimetotimeandwelikethem.Suchmeterscanbeausefulaccessoryforanyphotographerwhousesstrobes.However,theyhavetoomanydisadvantagestodependonthementirely.Likeanyothersophisticatedequipment,theycanbreakwhenweneedthemmost,especiallyaftertheyhavebeenknockedaroundinacamerabagonthewaytoalocationassignment.
However,abiggerdisadvantageisthatonmanylocationassignments,photographersoftenfindthemselveswithtoolittletimetoworkandtoomuchbulktomanage.Flashmetersworsenbothproblems.
GETTINGMORELIGHT
Wephotographerstendtowantmorelightthanwecanhave.Thisisespeciallytrueoflocationassignmentsbecausemobilityandavailableelectricalpoweroftenprecludecarryingallthelightingequipmentwewouldlovetohavewithus.
Therearetimes,ofcourse,whenallthatreallycountsishavingenoughlighttogetthepicture.Wehaveallbeenupagainstsuchsituations.Weknowbeforeweevenreleasetheshutterthatthelightingwillproduceharsh,high-contrastresults,but,duetosituationsbeyondourcontrol,suchlightingisthebestwecanget.
Sometimeagoweaccompaniedpoliceofficersworkinginabusyprecinct.Theyworkedatnightandwhenthingshappened,theyhappenedfast.Therewasnotimetothinktheshotthrough,notimetoputtheflashinanotherspot.Becausemostoftheactiontookplaceonthestreet,therewerenoceilingsorclose-bywallsfromwhichtobouncealight.Theonlyalternativewastouseaflashmountedonthecamera.
Whentheactionstarted,theonlythingwehadtimetodowasaimandshoot.Undersuchcircumstances,itwouldhavebeenfoolishtoworryaboutthe“qualityofthelight.”Allthatcountedwashavingenoughlighttorecordthesceneonfilm.
Anothertime,oneofuswenttoshootpicturesofjunglewildlife.Asinthebusypoliceprecinct,manyoftheanimalsbecameactiveatdusk.Onceagain,allthatreallymatteredwasbeingabletolightthescenewellenoughtogettheshot.
Thelistofsuchsituationscouldgoonandon.Examplescouldbedrawnfromalmostanykindofphotography.Butnomatterhowdiversesuchsituationsmaybe,thecommonthreadisthatyoumusthavetheamountoflightyouneedtomakethepictureyouwant.
Thefirstthingyoucandotoprovideasmuchlightaspossibleistousecommonsense:takethebrightestlightyoucanusepractically.Lessobviousisthatthisdoesnotsimplymeanusingasmanywatt-secondsaspossible.Somestrobeshavemoreefficientreflectorsthanothers;othersofferinterchangeablereflectors.Efficientreflectorscanmultiplylightoutputwithoutincreasingweight.
Inthecaseofhotshoestrobes,gettingallthelightyouneedusuallyboilsdowntotakingmorethanone.AnaccomplishededitorialphotographerIknowalwayscarriesthreeormore.Oneservesashiskeylightwhiletheothersprovidefillandilluminatethosepartsofthelocationhewishestoemphasizeinhiscomposition.Inonerecentshoothewasforcedtouseeightdifferentflashunitstogettheresults
hisclientdemanded.
FocusedFlash
Youcanalsouseaccessoriestofocusyourflashondistantsubjects.Thisisacommonlyusedtechniquewithwildlifephotographers.OneofthemostpopularusesaFresnellenstofocuslightfromacamera-mountedflashintoapowerful,far-reachingbeam.Withsuchaunititispossibletophotographanimals,andothersuchsubjects,ataconsiderablygreaterdistanceatnightthanitwouldbewiththeflashalone.
MultipleStrobes
Severalportablestrobestogetherproduceasmuchlightas,butallowmoreflexibilitythan,asinglestudiostrobe.Wecanusethemseparatelyasamultiple-lightsetup,aslargerlightsmightbeusedinthestudio,orwecangroupthemasaclustertobehaveasasingle,verypowerfulstrobe.
Today'shotshoestrobesareespeciallywellsuitedformultipleuse.Notonlydoestheirsmallsizeandlowweightmakethemrelativelyeasytocarry,italsomeansthatyoucanrigthemonlightweightlightstands.Andthatcanmakeahugedifferenceifthelocationatwhichyouaregoingtoworkisahardonetogetto.
Alongwithbeingrelativelyeasytocarry,hotshoestrobesarealsodesignedtoworkwelltogether.Onceyouinvestthetimeinmasteringhowtodoit,itisarelativelystraightforwardmattertogetabunchoftheselittletechnologicalwonderstoworktogetherthewayyouwant.Inaddition,therecentarrivalonthemarketofseveraldifferentradiocontrolsystemsallowsfarmoreflexibilitythanstandardinfraredlineofsightsetupsprovide.
IMPROVINGTHEQUALITYOFLIGHT
Theprevioussectionofferedsomesuggestionsforobtainingenoughlightusingthelimitedequipmentavailableformanylocationassignments.Theotherproblemcommontomosteasilytransportablelocationlightingequipmentisobtaininglightingthatlooksgood.Thuswewillnowmovefromquantitytoquality.
Locationlightingoftensuffersfromtwobasicdefects:illuminationthatistoohardandilluminationthatisuneven.Thehardlightingiscausedbytheneedtousesmallstrobesforportability.Unevenlightingistheresultofneedingtoilluminatelargerareaswithfewerlights.
Fortunately,tworelativelysimpletechniquescanbeusedtoproduceanacceptablequalityoflightwithmanyportablestrobes.Thesearebouncingandfeathering.Bothhelptoevenoutthelightinasceneandtoreduceunwantedshadows.
BounceFlash
Portableflashesare,bytheirverynature,smalllightsources,andsmalllightsourcesproducehard-edged,unattractiveshadows.Onewaytosoftentheseshadowsistobouncethelightfromawallorceiling,asshowninFigure10.1.Theceilingbecomestheeffectivelightsource.Becausetheceilingisa
muchlargerlightsource,itmakestheshadowsinthescenefarsofterandlessnoticeable.
10.1Bouncingthestrobelightfromaceilingorwallenormouslyincreasestheeffectivesizeoftheflash.Thiscausesshadowstobecomemuchsofterandlightstheroommoreevenly.
Althoughbouncedlightisgenerallyfarmoreattractivethandirectflash,itdoeshaveonemajordrawback:efficiency.Onereasonisthatthelighthastotravelfarther.Thedistancefromthestrobetotheceilingtothesubjectisfartherthanadirectpathfromthestrobetothesubject.Furthermore,partofthelightourstrobesprovideisabsorbedbytheceiling.Allthisaddsuptolesslightwhereweneedit.
Theamountoflightlostbyabsorptionandscatteringvariesaccordingtohowtheceilingispaintedandwhatitstextureis.Inmostsituations,however,compensatingbytwoorthreestopsisusuallyadequate.If,forexample,youareworkinginasituationinwhichyouwouldnormallyshootatf/8,theproperexposureisprobablyf/4.Openupabitmorefordarkerceilings.Ofcourse,thetechniqueusuallyproducesgoodpictureswhentheceilingisreasonablyneutrallycolored.
Iftheceilingisveryhighorifthesubjectisclosetothecamera,aceilingbouncewillcausedarkshadowsinthesubject’seyesockets.
Manyphotographersminimizethisdefectbyusingsmallbouncecards,suchastheoneweshowinFigure10.2.Theycanbeattachedtothestrobebyarubberbandortape.Inaddition,someofthenewerhotshoeflasheshaveabuilt-inbouncecard.Thisisagreathelpbecausetheyarealwaysavailablewhenyouwanttousethem.
Thesecardsbouncesomeofthelightdirectlyontothesubject'sface.Therestofthelightisbouncedfromtheceiling.Thecombinedresultisamoreevenlyilluminatedpicture.
Figures10.3and10.4showthesamesceneshotbothwithoutandwithabouncecard.
10.2Asmallbouncefillcardontheflashwillreducethefacialshadowscausedbybouncinglightfromtheceiling.
Anyreflectorthatisusefulinthestudioisalsolikelytoserveasagoodbouncecardonlocation.Youcanbouncestrobesfromthemandusethemtoreflectambientlightintoascene.Theonlyspecialrequirementisthattheybetransportable.Somereflectorscollapseorfoldforthispurpose.Themostcommonexampleisthelightingumbrella.
10.3Withoutabouncefillcard,bouncingthestrobelightfromtheceilingcausesunflatteringfacialshadows.
10.4Lookathowmuchlighterandlessobjectionablethebouncefillcardmakestheshadowsonoursubject’sface.
Biggerreflectorsareoftenusefuloutsidethestudiobecausemanyofthesubjectsarelarger.However,thebiggerthereflectoris,theharderitistotransport.Themostcreativesolutiontothisdilemmacomesfromaphotographerweknowwhooncerentedlargetrucksandparkedthemsothattheirsides
actedasfillcards.Evenifyouthinkthistacticisextreme,rememberitifyoudecidetobuyavan—considergettingawhiteone.
FeatheringtheLight
Featheringalightmeansaimingitsothatpartofthebeamilluminatestheforegroundandanotherpartlightsthebackground.Figure10.5showshowthistechniquecanbeused.
10.5Featheringthestrobelight.Thesuccessofthistechniquedependsgreatlyonthedesignofthestrobereflector.
Beforeexplainingfeathering,awordofcautionisdue.Howwellfeatheringworksorwhetheritwillworkatalldependsonhowtheflashheadisconstructed.Someofthelargerportablestrobesaremadewithlarge-diameter,circularreflectors.Theseusuallyscatteragreatdealoflightindirectionsotherthantowardthesubject.Suchunitscanalmostalwaysbefeatheredwell.
Ontheotherhand,manylightweightstrobeshaveverysmallflashtubessurroundedbyefficientlyfocusedreflectors.Thesedirectmostofthelighttowardthesubjectandwasteverylittleinotherdirections.Thistypeofbeamisfarlesswellsuitedtofeathering.Whatthismeansisthattheonlywaytofindoutifyourstrobecanbefeatheredistotryitout.Theprecedingwarningnoted,letusnowmoveontowhatisactuallyinvolvedinfeathering.
InFigure10.5,noticehowthestrongestraysoflightareemittedfromthecenterofthestrobehead.Ifthestrobeisheldattheproperangle,thesewillilluminatetherearofthescene.Thelightraysthatspilloutofthesidesofthereflectorarefarweaker.Theyilluminatethingsthatareclosertothecamera.Withalittlepractice,itisfairlyeasytolearnhowtoholdthestrobetoachievethedesireddegreeoffeathering.
ThereisstillanotherlessontolearnfromFigure10.5.Inityouwillnoticethattheflashisbeingheldashighaspossible.Thisisdoneto
10.6Holdingthestrobetoolowcausesdistractingshadowsonthewall.
10.7Holdingtheflashhighenoughcausesmanydistractingshadowstodisappear.
positionitsothatanyshadowsitslightcastswillbeasunobtrusiveaspossible.Thehigherthelightis,thelowertheshadowwillbecast.Thus,ifasubjectisstandingnearawallandtheflashisheldhigh,theshadowwillfallwherethecameracannotseeit.
WemadeFigures10.6and10.7ofthesamesubject,withthestrobeintwodifferentpositions.InFigure10.6,weheldtheflashlow,ataboutcameraheight.Noticetheverypronouncedanddistractingshadowonthewallthatthislightingproduces.NowlookatFigure10.7.Thistimewemadethepictureholdingtheflashashighaboveourheadaspossible.Noticehowthatactioncausedtheshadowtodisappear.
LIGHTSOFDIFFERENTCOLORS
Photographersinthestudiocarefullycontrolthecolortemperatureoftheirlight.Alllightsusuallyhavethesamecolorbalance.Addingotherlightswithgelsorlightsofanothertypeisadeliberateattempttoalterthecolor,notawhimoranaccident.
Photographersworkingonlocationmaynotbeabletocarefullycontrolthecolortemperatureofthelight.Theexistinglightinthesceneoftendoesnotmatchanystandardizedphotographiccolorbalance.Itmaybeimpossibletogetridoftheexistinglight.Eveninanindoorlocationinwhichtheexistinglightcanbeturnedoff,itmaybeessentialtoleaveitonforenoughlighttoilluminatealargearea.Thisnonstandardcolorhasunpredictableconsequencesifphotographersdonotanticipateproblemsandtakestepstodealwiththem.
WhyIstheColoroftheLightImportant?
Shootingacolorimagewithlightsourcesofdifferentcolorscanbeaseriousproblem.Whenwelookatascene,ourbrainscompensateforsomefairlyextremedifferencesinthecoloroflighttointerpretmostscenesaslitby“white”light.Thereareexceptions:ifyouaretravelingatdusk,withyourvisionadjustedfordimdaylight,youcanseethelightsofadistanthousetobetheorangecolorthattheyreallyare;ifyoustopatthathouse,however,andgoin,yourbrainwillimmediatelycompensateagainandyouwillseethelightaswhite.Toseewhythishappens,let’slookatthetwostandardlightcolors,tungstenanddaylight.
Tungsten
Thistermappliestoascenelitbytungstenbulbs.Thesetendtoberelativelyorange.Setfortungsten,thecamerawhitebalancecompensatesfortheorange.Usedwithtungstenlights,itproducespicturecolorsthatareclosetonatural.
If,however,weweretouseatungstenwhitebalancetoshootapictureilluminatedbydaylight,theresultingcolorwouldbenonstandard.Insteadoflooking“normal,”theentirescenewouldappearveryblue.
Tobeaccurate,wehavetopointoutthathouseholdtungstenbulbsalmostneverproducelightthatisthecolorofphotographic-standardtungsten.Theyaremoreorangewhentheyarenewandgetstillmoreorangewithage.Quartz-halogenlights,usedbyphotographersandtheaterproducers,dohaveaccuratetungstencolorandkeepthataccuratecolorthroughoutthelifeofthelamp.
Daylight
Daylightwhitebalanceproducesstandardcolorinascenethatisilluminatedbythesun.Obviously,sunlightisdifferentcolorsatdifferenttimesofdayandindifferentweatherconditions.Originally“standarddaylight”wassunlight,ataspecifictimeofday,ataspecifictimeofyear,ataspecificlocation,andonacloudlessday,inBritain.
Suchlightisrichinblue,andthatiswhytheskyonacleardayisblue.Adaylightcolorbalancecompensatesforthisandgivesthemostaccuratecolorreproductionusedwitheithermiddaysunlightorstrobe.Ifthisbalanceisusedwithtungstenlight,thepictureslookorange.
NonstandardLightSources
Photographersconsiderdaylightandtwoslightlydifferentcolorsoftungstenlighttobestandard.Alloftheothersarenonstandardtous.Unfortunately,“nonstandard”doesnotmean“unusual”or“rare.”Otherlightsarequitecommon.Wewilluseafewofthemasexamples.Thisdoesnotapproachacompletelistofnonstandardsources,buttheyshowthedangerswellenoughtokeepyoualerttothepotentialprobleminanylocationassignment.
Thefrequentmixoflighting,especiallyinmanymodernoffices,istherootoftheproblem.Thedigitalcameracancompensateforthecolorofalmostanynonstandardlight.Furthermore,itcancompensateforalmostanyevenmixoflightcolors.
Thedifficultycomesfromanunevenmix:partofthesceneislitbyonelight,andotherareasarelitbylightsofothercolors.It’sexpectingtoomuchtowantthecameratofixsuchproblems,andwehavetothinkbetterthanthecameradoestofixthemourselves.Thefollowingaresomecommonlightsourceswecallnonstandard.
Fluorescenttubesarethenonstandardlightsourcephotographersencountermostfrequently.Thelightproducedbyfluorescenttubespresentsphotographerswithaspecialproblem.Inadditiontobeingnonstandard,itcomesinmanydifferentcolors.Agechangesthecoloroffluorescenttubesslightly.
Furthermore,peoplereplaceburned-outtubeswithnewonesofanothertype.Afterafewyears,asinglelargeroommayhaveseveraldifferenttypesoftubes.Awhitebalancethatisgoodforanyparticulartypeoftubemaybebadfortherest.
Asarule,thelightfromthesetubestendstohaveastronggreencast.Thiscanproducesomeparticularlyunpleasantnonstandardcolorswheneithertungstenordaylightfilmisused.People,inparticular,tendtolookawfulwhentheyarephotographedunderuncompensatedfluorescentlighting.
Nonstandardtungstenlightismorecommonthaneitherofthephotographicstandardtungstencolortemperatures.Ordinarytungstenbulbsaresignificantlymoreorangethanphotographicbulbs,andtheygetmoresoastheyage.Thedifferenceisenoughtomatterwhenevercolorbalanceiscritical.
Nonstandarddaylightdoesnotsurprisemostpeople.Weallknowthatsunlightismuchredderatdawnanddusk.Whatsurprisesmostof
usmoreislearningthatdaylightcanbeverynonstandard,eveninthemiddleofabrightday.
Figure10.8illustratestwodifferentkindsofdaylight.Thehouseonthelefthasdirectsuncomingthroughawindowontothesubject.Suchdirectlightfromthesunwillbeslightlywarm.Itwillhaveaslightlyredtoyellowcolorbias.Ontheright,weseeadifferent“daylight”situation.Thistimethesubjectisbeinglitbylightthatcomesfromtheblueskyratherthanthesun’sdirectrays.Thislightisdecidedlycool.Ithasagooddealofblueinit.
Bothofthesesubjectsareilluminatedbydaylight.Theonlyproblemisthattheso-calleddaylightisverydifferentineachofthem.Eachproducesapicturewithadifferentcolorbalance.Thecauseoftheproblemisthateachsubjectlackspartofwhatweacceptasstandarddaylight.
Whenphotographersusethetermdaylightwemeanlightthatismadeupofacombinationofraysthatcomedirectlyfromthesunandthosethatcometousfromtheskyaroundit.Intheprecedingexample,eachsubjectwaslitbyonlyoneofthetwopartsofthatcombination.
Anothercommoncauseofnonstandarddaylightisfoliage.Subjectsshadedfromthedirectsunlightmaystillbeilluminatedbytheopensky.
10.8Thedirectsunlightstrikingthehouseontheleftiswarmcolored,noticeablybiasedtowardyellow.Lightreachingthehouseontherightcomesfromthebluesky,anditwillhaveamuchcooler,blue-biasedcolor.
Thiscausesthesameblueshiftwesawinthesubjectontherightintheprecedingexample.Thisproblemiscompoundedbygreenleavesfilteringandreflectingwhateversunlightdoesreachthesubject.Inextremecases,theresultlooksmorelikefluorescentlightthandaylight.
Onceagain,thecolorerrormaynotbesignificantinmanycases,butwehavetothinkaboutthe
importanceofaccuratecolorineachsceneanddecidewhethertheproblemneedsaremedy.
DotheColorsMix?
Therearetwobasicsituationsthatweencounterwhenworkingwithdifferentcoloredlightsources.Thefirsthappenswhenweusewhatwewillcallunmixedcolor;thesecondoccurswithmixedcolor.Asyouwillseeshortly,unmixedandmixedcolorpresentdifferentchallenges,andtheyarehandledindifferentways.
Mixedcolorlightingisjustwhatthenameimplies.Itoccurswhentheraysoflightwithdifferentcolorbalancesmixorblendtogethertoproduceacolorbalancedifferentfromthatofanysinglelightsource.
Figure10.9showshowlightsourcescanmixtogetherinthisway.Fluorescenttubesprovidetheambientillumination.Astrobeis
10.9Mixedstrobeandfluorescentilluminationproducesevenlycoloredlight.
10.10Mixedcoloriseasytocorrect,ifeverythingislitroughlyequallybyallsources.
bouncedfromtheceiling.Thebouncedstrobeilluminatesthescenemuchasthefluorescenttubesdo.Thelightraysfromtheflashtubemixwiththoseproducedbythefluorescenttube.Theresultisafairlyevenilluminationthroughoutthescenebylightofadifferentcolorbalancefromeithertheflashorthefluorescenttubesalone.WeshotFigure10.10withevenlymixedlightsources.Everylightwas“wrong”forphotography,butthemixwaseasyenoughtocorrect.
UnmixedcolorisdiagrammedinFigure10.11.Thesceneisthesame,butthestrobeisnowdirectedatthesubject,nottheceiling.Thisisacommonexampleofascenethatisilluminateddifferentlybyeachofthetwolightsources.
Noticeinthediagramthatthebulkofthesceneislitbyoverheadfluorescentbulbs.However,theforegroundsubjectandhisimmediatesurroundingsarelitbytheflash.
Theresultistwoverydifferentlycoloredareasinthepicture.Theforegroundsubjectandhisimmediatesurroundingswillbeilluminatedbytherelativelyblue“daylight”fromtheelectronicflash.Therestofthescenewill,however,receivethegreenlightfromtheoverheadfluorescents.Theproblemisthatthecameracanbebalancedforonlyonelightsource.
10.11Usingtheflashasshownherewillproduceapictureinwhichdifferentpartsofthescenearelitbyverydifferentlycoloredlight.Thiscancauseseriousproblemsincolorphotography.
Sometimesunmixedlightingcanoccurwhenwedonotexpectit.InFigure10.12,thewallbehindthesubjectisnotagreatdealfartherfromthestrobethanthesubjecthimself.Wemightexpecttohavethesamemixofstrobeandambientlightoneverythinginthepicture.
Notice,however,thatthestrobeandthefluorescentlightcomefromdifferentdirections.Thestrobecastsashadowonthewall,butthefluorescentlightilluminatestheshadowandmakesitgreen.
TheRemedies
Bothmixedandunmixedlightsituationsarecommon,anditisimportanttobeabletohandlebothofthem.Weuseaslightlydifferentremedyforeach.
10.12Becausethefluorescentlightilluminatestheshadowthestrobecastsonthewall,theshadowwilllookgreeninacolorphotograph.
CorrectingMixedColors
Mixedcolorsituationsarerelativelyeasytohandlebecausetheimproperilluminationthatresultsfromthemisuniformthroughoutthescene.Inotherwords,theentiresceneislitbylightthathasthesamecolorbalance.Thecolorbalanceofthewholepicturewillbewrong,butallpartsofthescenewillbewronginthesameway.
CorrectingColorwhileShooting
Itisthisuniformityoferrorthatmakestheproblemsosimpletocorrect.Thecamerawillprobablyfixitforyou.Ifitdoesn't,itwillbecloseenoughthataslightwarmingorcoolingoftheimagewillfixit.Theresultwillbeapicturethathasthecorrectcolorbalanceandinwhichcolorswithinthescenereproduceinastandard,orrealistic,way.
CorrectingColorafterthePictureIsShot
Becauseanycolor-balanceproblemsareuniformwhenmixedcolorsareused,itisrelativelysimpletomakeanyrequiredcoloradjustmentsduringpostproduction.Thisgivesyouausefulsafetymarginshouldyoufail
togetthepropercorrectionwhenyouareshootingthepicture.Thecolorbalancemaynotbequiteasgoodasapicturethatwasshotrighttobeginwith,butitislikelytobegoodenoughthatanexperiencedviewercannottellthedifferencewithoutaside-by-sidecomparisonofthetwo.
Onecautionisdue,however.Bewareofthosescenesthatincludealightsourceorthemirrorreflectionofone.Theseextremelybrightareasrecordinthepictureaswhitehighlights,regardlessofthecolorof
thelightproducingthem.Thesehighlightsmaythentakeonthecolorofwhatevercorrectionisusedtoremedytherestofthescene.
Youcandealwiththisproblem,butitrequiresmorethanthestraightforwardcoloradjustmentmostpeopleknowhowtodointheirimageeditingsoftwareandisatopictoofarfromphotographiclightingtodealwithinthisbook.Evenworse,onlythebestoffsetprintershaveprepressdepartmentswhocandealwithit.Thewaytobesuretogetitrightistoeithercorrectthecolorwhileshootingthepictureortocomposeitsothatitdoesnotcontainanytroublesomehighlights.
CorrectingUnmixedColors
Nowhitebalanceadjustmentcancorrectunmixedcolor.Whatevercorrectionisrightforoneareaiswrongforanother.Tryingacompromisewhitevaluebetweenthetwoproducesjustthat:acompromiseinwhichnothinginthesceneisquiteright.Youcanoftencorrectthecolorbalancelocallyinimageeditingsoftware—alittlemorebluehere,moreyellowthere—butthat’stediousandit’sbesttoavoiditwhenyoucan.
MakingtheSourcesMatch
Thebestwaytocopewithunmixedcolorsourcesistofilterthelightstomatcheachotherascloselyaspossible.Theobjectiveofthisistogetallofthelightsourcestobeasinglecolorbutnotnecessarilytherightcolor.Thenletthecameraadjusttheoverallscenetoberight.
Thus,ifwewerefacedwithsituationssuchasthoseinFigure10.11or10.12,wecouldcovertheflashwithalightgreentheatricalgelthatapproximatelymatchesthecolorofthefluorescent.(ThegelcoloriscalledToughPlusgreen,equaltoCC30G.)Thisaddsenoughgreentomakethestrobelightapproximatethecolorofmanyoverheadfluorescents.Thentheentiresceneislitbylightofatleastsimilarcolor.Thecameracanprobablygetthecolorcloseenoughthatwhateveradjustmentweneedtomakeisminor.Evenbetter,wecanmakeaglobalcolorcorrectionfortheentirescenewithoutindividuallyretouchingeachiteminthepicture.
Thefilterwesuggesthereisasolutionthatfrequently,butnotalways,works.Thespecificfiltrationvarieswiththescene.Aswasthecaseearlier,theonlyreallysatisfactorywayofdeterminingexactlywhatfiltertouseisbytrialanderror.
FilteringtheDaylight
Rememberthatwindowsarelightsourcesandthattheycanbefilteredlikeanyotherlightsource.Motionpictureandvideophotographersdothisroutinely,butstillphotographerstendtooverlookthepossibility.
Considerasceneinwhicharoomislitbytungstenphotographiclightsandbydaylightcomingthroughopendoorsorwindows.Aquicksolutionwouldbetousebluegelsonthephotographiclightstomakethemmatchthedaylight.Thenthescenecouldbeshotatadaylightwhitebalance.However,ourlightsareprobablyweakerthanthesun,andwewouldprefernottodimthemevenmorewiththelightabsorbedbythefilter.Abettersolutionwouldbetoputorangetheatricalgelsontheoutsideof
thewindowandthenshootwithatungstenwhitebalance.Thisaccomplishesthesamebalancingoflightcolorsbutbetterbalancestheintensityofthetwosources.
CorrectingErrorsinReproduction
Ifthecolorisunmixed,thisistheworstsolution.Useitonlyasalastresort.Nosinglecorrectionwillworkfortheentirescene.Localcorrectionwithinthescenecanbefunwhenyouarelearningimagemanipulationsoftware,butitcostsextratime,money,orboth.
LIGHTSOFDIFFERENTDURATION
Photographersoftenusephotographiclightandexistinglighttogethersothatonesourceisthemainlightandtheotheristhefill.Measuringtherelativebrightnessofthetwoiseasyifbothlightsareturnedoncontinuously.Thisistrue,forexample,ifthetwosourcesaresunlightandtungsten.
However,ifthephotographiclightisstrobeinsteadoftungsten,comparingitsbrightnesswiththedaylightismoredifficult.Thedaylightis“on”continuously,butthestrobelightsforonlyafractionofasecond.Wecannotseetherelationshipbetweenthetwo.
Figure10.13showsacommonoutdoorshootingsituationinwhichstrobesareuseful.Whenweplacedthemodelwherewedesired,hewasbacklit.Asaresult,anormalexposurewasfartoodark.
10.13Thecompositionwewantedcalledforthemodeltobebacklit.However,withanormalexposure,thisarrangementproducedapicturethatwasfartoodark.
Thereweretwowaysinwhichwecouldhavecorrectedthispicture.Onewouldhavebeentoincreaseourexposuresubstantially.Thisexposurecorrectionwouldhavelightenedthesubject,butitalsomighthavecausedseriousflarefromthesunlightcomingthroughthetrees.
Ourotheralternativewouldhavebeentouseastrobetofillintheshadow.Figure10.14showstheresultofsuchlighting.Thefillflashdidjustwhatwewantedittodo.Itallowedustoproduceapictureinwhichboththebackgroundandthesubjectareproperlyexposed.Giventhattheuseofafillflashwasagoodideainthissituation,thenextquestionishowtocalculatetheproperexposureforthepicture.Howwereweabletoselectanexposurethattookintoaccountboththeambientdaylightpresentinthesceneandourstrobeoutput?Keepthefollowingpointsinmind:
•Insituationssuchasourexample,thestrobeexposurewillbedeterminedalmostexclusivelybytheaperture.Theflashistoobrieftobesignificantlyaffectedbyshutterspeed.
•Theambientlightexposurewill,ontheotherhand,bedeterminedbyacombinationofboththeapertureandtheshutterspeed.
10.14Afillflashproducedanexposureinwhichboththesubjectandthebackgroundareproperlyexposed.
Ifyouphotographapoliticalleaderdashingtohislimousineafterhisfraudindictment,youwillcertainlyletthecameradeterminethebalancebetweenyourstrobeandtheambientlight.Ifyouphotographaroominteriorforthecoverofafurniturecatalog,youwillcarefullybalancetheambientandartificiallight.Increaseyourshutterspeedformoreoftheambientlight.Decreasetheshutterspeedforlessambientlight.Ifthechangeinshutterspeedmakestheimagetoolightortoodark,thenadjusttheaperturetocompensate.
ISSTUDIOLIGHTINGPOSSIBLEONLOCATION?
Yes,ofcoursestudiolightingispossibleonlocation,butitmayrequiremuchmoreworktoachieveit.Controlismoredifficult.Habitandexperiencesometimeswillnotsubstituteforcalculation.Testingandreshootingaresometimestheonlywaystogetthebestresults.Whateverittakestogetthoseresults,wehopethischapterhelpsyouachievethem.
Goodpicturesrequiremorethangoodlighting.Whenwehaveevenlesscontroloverthesubjectthanwedothelight,speedandspontaneitycancountmorethantechnicalvirtuosity.Thesuccessofthepicturedependsonbeingabletorecordthecriticalinstant,nottheinstantjustafterit.Sowealsohopeyoucanusesomeoftheshortcutsinthischaptertogetthepicturebeforethepicturegetsaway.
Eitherwayisgoodattherighttimeandplace.
Thisisthemostimportantmessageinthisbook.Thereisno“correct”waytolightascene,justasthereisnodecidedly“right”cameratouse.Goodphotographershaveatoolboxofideasandtechniques.Theypickfromthattoolboxaccordingtothetaskofthemoment.
Wewillnotmindifyouneverlightasinglesubjectexactlyaswehaveinourexamples,butwedowantyoutohaveourtoolboxofideastouseasyouplease.Helpyourself.