ravensbourne 2012 quality control guidelines v1.1
TRANSCRIPT
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Ravensbourne2012
HighDefinitionProgrammingTechnicalStandards
forProgrammeDelivery
Version1.1
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1Introduction 3
2TechnicalResponsibilitiesforProgrammes 4
2.1GeneralResponsibilities 4
2.2Exemptions 4
3GeneralTechnicalRequirements 5
3.1VideoStandard 5
3.2VideoLevelsandGamut 5
3.3AspectRatio 5
3.4SafeAreasforActionandCaptions 5
3.5Time-code 6
4AudioGeneralTechnicalRequirements 6
4.1AudioStandards 6
4.2AudioLevel,ReferenceLevelandMeasurement 6
4.3Line-upTones 6
4.4SoundtoVisionSynchronization(Lip-Synchronization) 7
5GeneralQualityRequirements 7
5.1TechnicalQualityGrading 7
5.2GeneralVisionQualityRequirements 85.3GeneralAudioQualityRequirements 9
5.4FlashingImages/VisualPatterns-PhotosensitiveEpilepsy(PSE)
9
6Submission 10
6.1Line-upTestSignals,ClockandLeader 10
6.2CopyrightLegislation 10
6.3TechnicalAcceptanceProcedures 10
6.4SubmissionProcedure 116.5Feedback 11
6.6SubmissionDates 11
Appendix A 12
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1Introduction
Thisdocumenthighlightsanddefinesthetechnicalstandardsrequiredforallhigh
definition(HD)programmescommissionedforbroadcastingduringthe
Ravensbourne2012Event.Thisdocumentappliestobothliveandpre-recorded
programmes.
Thisdocumentincludesbothtechnicalandproductionspecificationstobeusedasa
simplereferenceforoperationalstaffandengineersinvolvedwithcontentcreation.
Pleasenotethisdocumentdoesnotcontainguidelinesforprogrammecontent.For
theregulationsonprogrammecontentpleaseseetheOfcomBroadcastingCode
whichcanbefoundhere:
http://stakeholders.ofcom.org.uk/broadcasting/guidance/programme-
guidance/bguidance/
Pleasenotethatthesecompliancestandardsmustbemetinorderforcontenttobe
broadcast.
AswellastechnicalrequirementsthisdocumentalsoincludesOperationaland
Qualitystandardstoaidproductionsandensurethattransmittedmaterialisnotonly
compatiblewithtransmissionequipmentbutalsoofhighqualityandlegalto
broadcast.
PleaserefertotheAppendixonpage12formoreinformationhighlightedinthis
document.
Ifthereareanyareasofthedocumentthatareunclearoryouhavefurther
questionsaboutthenpleasecontactoneoftheHeadsofQualityControlfor
Ravensbourne2012(see2.1TechnicalResponsibilitiesforProgrammes.)
Thestandardssetoutinthisdocumentmustbemetotherwisethecontentwillnot
befitforbroadcastandare-editoftheprogrammethatcomplieswiththe
guidelineswillbeaskedfor.Anyproblemswithprogrammesreceivedwillbeclearlyoutlinedandhelpfuladvicewillbegiventoensurethatprogrammescomplywith
thesestandardsandcanbetransmitted.
Thisdocumentreferstothreetypesofstandardsaslaidoutbelow:
1. TechnicalRequirements-ThisdescribesthetechnicalstandardsrequiredforRavensbourne2012sothattheprogrammecanbeprocessedeasilywithin
thesystem.Thesearepass/failobjectivemeasurements.
2. QualityRequirements-Thisdealswithqualityissueswiththepicturesandthesound.TojudgethiswewillbeusingtheCCIR-5pointgradingscale.
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(Pleasesee5.1formoreinformationontheCCIR-5gradingscale.)
3. OperationalRequirements-Thisdealswithdeliverystandardssuchastheline-upsequencesandmetadata(anydatawhichdescribes,refersor
attachedtotheprogrammefiles.)
2TechnicalResponsibilitiesforProgrammes
2.1GeneralResponsibilities
TheHeadsofQualitycontrolarerequiredtoensurethatprogrammetechnical
qualityismaintainedtoasatisfactorystandard.ItistheHeadsofQualitycontrols
responsibilitytoclearlyoutlineanyissueswithprogrammesandgivehelpful
guidanceforanychangesthatmayneedtobemade.
TheHeadsofQualityControlforRavensbourne2012are:
NileHamilton JonathonReed
07776448807 07899842254
[email protected] [email protected]
2.2ExemptionsAlthoughallprogrammesareexpectedtomeetthestandardsoutlinedinthis
documentexemptionscanbemadeinsomecases.
Thecriteriaforexemptionfromthestandardsisstrictandisnotflexible,alsoitmay
notbeusedfortheconvenienceofprogrammemakers.Thesearethecategoriesfor
technicalexemption:
HistoricInterest-Programmesthatusearchivematerialtosupporttheprogrammecontent.Thisincludesfootagefrompreviousproductionswhere
currentqualitystandardscouldnotbemetduetotheequipmentatthetime.
ActualityMaterial-Featuresordocumentarieswherebroadcastqualityhasnotbeenpossibleduetolimitationssuchastheformatorphysicalsizeor
valueofequipment.
DomesticEquipment-Programmesthatuseexcerptscreatedbyconsumerqualityequipment,whichfitsinwiththecontextoftheprogramme.
Pleasenoteifaprogrammecontainscontentthatrequirestechnicalexemption
pleasecontactaHeadofQualityControlbeforetheprogrammeissubmittedbriefly
explainingthereasonsforthecontent.
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3GeneralTechnicalRequirements
Thesetechnicalrequirementsmustbemetsothatmaterialcanbepassedthrough
transmissionsystemsreliablyandwithaslittlenoticeableimpairmentsaspossible.
Thisallowstheendusertoviewmaterialinthebestpossiblequality.
3.1VideoStandard
Allprogrammesshallbeofthe1920x1080interlacedat25framespersecond(fps)
standardotherwiseknownas1080i/50andintheAppleProRes4:2:2HQcodec
unlessotherwiseagreedwiththeHeadofQualityControl.Signalswillbeassessed
accordingtotherecommendationITU-RBT.709-5.
(SeeAppendix3.1formoreinformationaboutITU-RBT.709-5)
3.2VideoLevelsandGamut
Videolevelsincludingline-upmustfallwithinthespecifiedlimitssothatthe
programmematerialcanbeusedwithoutadjustment.
VideolevelsarebasedonthePALSystemIwhichspecifies0to100%RedGreenBlue
orRGBLimits.
SignalsmustmeetEBURecommendationR103-2000,whichstates:
Luminancelimitsfrom-1%and103%
Chrominance105%max-RGBvaluestonotexceedlimits-5%to+105%.
(SeeAppendix3.2.1formoreinformationaboutLuminanceandChrominance)
Thevideoshouldnotsufferfromcompositeerrorssuchascrosscolour,banding,and
moir.
(SeeAppendix3.2.2forabriefdescriptionofcommonvideoandaudioerrors)
3.3AspectRatio
ThetechnicalstandardaspectratioforRavensbourne2012is16:9.Fullprogrammes
in4:3aspectratiowillnotbeaccepted.Formatchangeswithintheprogrammewill
alsonotbeaccepted.
Programmesin16:9maycontainshortsectionsoffloating4:3materialbutitmust
bePillarboxed.Theprogrammemustnotincludeblackbarsatthetoporbottomof
thepictureasthiscancauseunwantedzoomingonsomeTVsetswhichhaveauto-
zoomfunctionsenabled.
(SeeAppendixforpillarboxingguidance.)
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3.4SafeAreasforActionandCaptions
Allprogrammeswillbeinthe16:9formatandthereforemustbeprotectedfor14:9safearea.
Allcaptionsandmainprogrammeactionshallbewithinthesafeareas.
Anylogos,titlesorcaptionsfoundtobeoutsidethe14:9safetyareawillresultinan
automaticfail.
(SeeAppendix3.4.1forsafetyareaguidance)
3.4Time-code
TimecodeshouldconformtoEBUspecification12M-2(SMPTE12M2-2008) ProgrammestartshouldbeatTimecode10:00:00:00 Timecodemustnotspanacrossthemidnight(00:00:00:00)boundaryasthis
createstwodifferentsetsoftime-codesforthesameprogramme.
Alltime-codesmustmatchincludingLTC,DVITC,ATC.
(SeeAppendix3.4.2forusefulreferencesregardingTimecodespecifications)
4AudioGeneralTechnicalRequirements
4.1AudioStandards
Programmesshallbedeliveredindualmonoorstereoformatat48kHzperchannel.
LeftaudioshallbepresentontheAlegorChannel1.
RightaudioshallbepresentontheBlegorChannel2.
MonoshallbeinDualMonoformatwithidenticalandphasecoherentaudioonboth
LeftandRightchannelstomatchupamongststereoprogrammes.
Finishedprogrammematerialintendedfortransmissionwithstereosound,whether
recordedorforlivetransmission,mustcarrysoundinA/B(Left/Right)form.M/S
(Mid/Side)isnotacceptablefordelivery.
4.2AudioLevel,ReferenceLevelandMeasurement
ForDigitalAudiothereferencelevelis18dBbelowthemaximumcodingvalue
(-18dBFS)asperEBUrecommendedpracticeR68.Referencelevelisreferredtoas
ZeroLevel,Line-upLevel,0dB,0dBuorPPM4.
ProgrammeaudiolevelsshouldbemeasuredusingPeakProgrammeMeters(PPM)
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toBS5428.
(SeeAppendix4.2.1formoreinformationonBS5428)
TheMaximumorPeakProgrammeLevelshallneverexceed8dBsabovethe
ProgrammesReferenceLevel(i.e.PPM6or-10dBu).
ProgrammeaudiolevelshouldnotdropbelowZeroLevelorPPM4foranylonger
than10seconds.
(SeeAppendix4.2.2formoreinformationonPPMaudiolevelsandDigitalaudio
levels)
4.3Line-upTones
Line-upTonesservetoidentifyindividualsignalchannelsandtoprovidereferencelevelstoindicatethatwithoutadjustmenttheprogrammetransmittedwillbewithin
thesignallevellimitsspecified.
Alltonesmusthavebeensourcedtoatoleranceof+/-0.1dB.
StereoLine-upToneshallbeatafrequencyof1kHz+/-100Hzandshallindicatethe
LeftandRightprogrammelegswithEBUStereoToneat8dB(PPM4/ZeroLevel)
withonlytheleftlegidentifiedby250msbreakseverythreeseconds.
Alltonesmustbesinusoidal,freeofdistortionandshallbephasecoherentbetween
channels.
(SeeAppendix4.3formoreinformationonTonereferencelevels)
4.4SoundtoVisionSynchronization(Lip-Synchronization)
Therelativetimingofsoundtovisionshouldnotexhibitanyperceptibleerror.
Programmesshouldbecheckedforanynoticeablesyncerrorsbeforesubmission.
Soundshouldnotleadorlagthevisionbymorethan10ms.
5GeneralQualityRequirements
Thefollowingprinciplesofexcellenceapplytobothaudioandvideo.
Programmesshallbecapableofmeetingthegradingrequirementsasgivenbythe
ITCusingtheCCIR5-pointgradingscale,whichstates-Liveprogrammesusing
systemsthatmeettheperformancefiguresintheITCHandbookshouldachievea
soundandvisiongradeof5.Recordedprogrammesbasedonelectronicproduction
shouldachieveagradeofatleast4.Theabsoluteminimumqualitythatisnormally
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acceptableisgrade4.
Ravensbourne2012Managementreservestherightnottobroadcastprogrammes
whichinitsopinionaretechnicallyunacceptable.Theprogrammecreatorswillbe
notifiedifaprogrammefailstheseprinciplesofexcellence.
TheCCIR5-pointgradingis:
Quality Impairment
5-Excellent. 5-Imperceptible.
4-Good. 4-Perceptiblebutnotannoying.
3-Fair. 3-Slightlyannoying.
2-Poor. 2-Annoying.
1-Bad. 1-Veryannoying
TypicalFactorsthatDepictGrading
VideoHopandWeaving
Jittering
Drop-Out
Streaking
VideoNoise
ColourCastandShadingErrors
MixedLighting
Vignetting
Over-Exposure
Under-Exposure
PoorDefinition
SoftPictures
CrushedBlackLevel
LowContrast
Saturation
(SeeAppendix3.2.2formoreinformationregardingcommonerrorsofvideoand
audio)
PriortosubmissionprogrammecreatorsmaywishtoQCtheirownwork,please
notethatpicturemonitorsonwhichvideoparametersareassessedandgradings
madeshouldbegrade1(referenceEBUTech3263-E)andlineduptoprofessional
standards.APLUGE(PictureLineUpGeneratingEquipment)signalshallbeused
priortotheassessmenttoensureproperadjustmentofbrightness,contrastand
greyscale.
Pleasenoteagrade1picturemonitorislocatedintheQualityControland
Presentationroomlocationonthe2ndflooratRavensbourne.
5.2GeneralVisionQualityRequirements
Byitsnaturethisisasubjectivearea.Allpresentedcommissionedprogrammeswill
begradedsubjectively.Acompetentpost-productionprovidershouldbeableto
makeaneducatedviewduringediting.
Theseguidelinesarenottoprohibittheuseofanyproductiontechniquesorto
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preventinnovativeprogrammingprovidedthatasuitablequalityisachieved.
Ingeneral:
a)Thepicturemustbesharpandwelllit(unlessartisticconsiderationsrequireotherwise)
b)Thevideosignalmustbefreeofblackcrushingandhighlightcompression.
Transientresponseshallbesuchthatstreaking,ringing,smear,echoesand
overshootsarenotnoticeable.Moirandotherpatterningshallnotbevisible.Hum,
crosstalkandotherspurioussignalsmustnotbeapparent.
c)Colourrendition,especiallyskintones,mustbearealisticrepresentationofthe
sceneportrayedunlessartisticconsiderationsrequireotherwise.
d)Videoprocessing(e.g.effectsdevices)mustnotintroduceunintentionalchanges
toluminanceandchrominancelevelsnorcauseperceptibletimingshiftsonentryor
exitfromtheeffect.e)Appropriateaudioorvideodelaymustbeusedtocompensateforlip-syncerrors.
f)Theremustbenovisiblecontouring/artifactscausedbymultipleD-A(Digitalto
Analogue)andA-D(AnaloguetoDigital)conversionsorcompression.Quantisation
Noiseshallnotbeapparent.Ingeneral,recordingsmadeoff-airfromdigital
sources(DTT,DSATandD-Cable)shouldnotbeincorporatedintonewprogramming
asthesesignalshavealreadybeensignificantlycompressed.
PleasenotifyaHeadofQualitycontrolbeforesubmissionexplainingthereasonsfor
anyexemptionsthatneedtobeconsidered.
5.3GeneralAudioQualityRequirements
a)Theaudioshallbefreeofspurioussignalssuchasnoise,humandcross-talk.
b)Sibilanceanddistortion,wowandfluttershallnotbeapparent.
c)Theaudioshallnotshowdynamicandfrequencyresponseartifactsasaresultof
theactionofnoisereductionorlowbitratecodingsystems.
d)Audiocompressionshouldbeusedaslittleaspossibleastheeffectsof
compressionusedforbroadcastdistributionandtransmissioncanexacerbate
impairments.
e)Dynamicrangeshallnotbeexcessive.Itshallbesuitableforthewholerangeofdomesticlistening.
f)Careshallbetakenwhenincorporatingbackgroundmusicandeffectswith
dialogue,orpeoplewithahearingimpairmentandpoorlisteningconditionscanfind
thedialoguedifficulttohear.
(PleaserefertoAppendix3.2.2forcommonVideoandAudioerrorsandtheir
descriptions)
5.4FlashingImages/VisualPatterns-PhotosensitiveEpilepsy(PSE)
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Flickeringorintermittentlightsandcertaintypesofrepetitivevisualpatternscan
causeseriousproblemsforsomeviewerswhoarepronetophotosensitiveepilepsy.
Televisionisbynatureaflickeringmediumbutstepscanbetakentoreduce
unnecessaryrisksandtoreducetheincidenceofseizurestoanacceptablelevel,
althoughtheycannotremovetheriskentirely.
TheITC(UK)issuesguidelinesforPSE.Thefollowingguidanceonthemajorfactors
involvedisprovidedforreference.However,theITCguidelinesshouldbeconsulted
forcompleteinformation.
Rapidlyflickeringimagesshouldnotchangeatafastrate(i.e.lessthan9frames
betweeneachflash).
Iftherearemorethan6flashespersecondthenthematerialwillfailimmediately
andberejected.
Thisappliesacrossallsubmissions
Ifbrightnesschangesforagivenareaofapictureislessthan25%ofscreenmaximumbrightnessthenthatareamaybediscounted.
Inmarginalcasessuchimagesshouldbeavoidediftheyarepositionednearthecentreofthescreen.
Changesincolourarenotaproblemunlesstheyaffecttheredchannelsubstantially.
Prominentandregularpatterns,whichcoveralargeproportionofthepicturearea,shouldbeavoided,especiallyiftheyrepresentbars,spirals,ordartboardpatterns.Movingorflickeringregularpatternsareparticular
hazardous.
Careneedstobetakenalsowithcomputer-generatedimages,which,ifhighlydetailed,cancauseahighdegreeof25Hzinter-lineflickerinthe
displayedtelevisionpicture.
Videoluminancelevelasmeasuredonawaveformmonitordoesnotsimplyequatetoscreenluminance(brightness)andcannotbeusedtoassess
brightnesswithoutcorrectingforGamma.
ThefollowinglinkisausefulguideregardingPSEandtelevision
http://www.hardingfpa.com/resources/broadcast-guidelines/
6Submission
6.1Line-upTestSignals,ClockandLeader
Thestartofprogrammeandanysubsequentpartshouldbeprecededbya
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countdownclockindicatingprogrammeproductionnumber,programmetitleand
programmeproducersname.
Theclockmustprovideaclearcountdownof10secondswiththefirstframeofthe
programmelaidbackthreeseconds.Theclockmustappearroundwhenviewedona
16:9display.
Timecode Duration ActivePicture AudioChannels1&2
09:59:17:00 00.30seconds EBUHDColourBars(75%) Constant1kHzTone
09:59:47:00 00.10seconds IdentandClock Silence
09:59:57:00 00.03seconds Black Silence
10:00:00:00 ProgrammeStart ProgrammePicture ProgrammeAudio
Pleasenote:Attheendoftheprogramme,soundmustendnaturallyorbefadedout
bytheendoftheprogramme.Thereshouldbeafreezeorlivingholdfor10seconds.
6.2CopyrightLegislation
Itistheprogrammemakersresponsibilitytoensurecopyrightlawsarenot
breached;thisincludesliteracy,music,soundrecording,films,plagiarismetc.All
programmesmustabidebythecurrentCopyright,DesignsandPatentsAct1988.For
moreinformationpleasevisit:
http://www.copyrightservice.co.uk/copyright/p01_uk_copyright_law
6.3TechnicalAcceptanceProcedures
EveryprogrammesubmittedmustpassQC.Anyprogrammenotmeetingthe
requiredstandardwillbereturnedtotheprogrammemakerforamendment.Each
failedprogrammewillreceivefeedbackonfailedcriteria.Asubsequentreviewwill
thenbecarriedouttocheckthatanyworkhasbeendonesatisfactorily.
Programmes,whichdonotpassQC,willnotbebroadcastunderanycircumstances
untilrequiredchangesaremadeandtheprogrammeispassed.
6.4SubmissionProcedure
AllcontentmustbesubmittedforQCviatheFORKMediaAssetManagement
(MAM)system.
Oncetheprogrammeiscompleteandhasbeenrenderedouttowiththeformat
specifiedinthisdocument(see3.1VideoStandardand4.1AudioStandards)ingest
andaddtotheMAMwiththefollowingfilenamestructure:
RAVE2012_PROGRAMMENAME_VERSION_SURNAMEOFHEADPRODUCER
ForExample:RAVE2012_PRERECORDEDPROGRAMME_V1_REED
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FILESMUSTBEINTHISFORMATORTHEYCANNOTBEQUALITYCONTROLLED.ITIS
YOURRESPONSIBILTYTOUPLOADFILESWITHTHECORRECTFILENAME.
6.5Feedback
Feedbackwillbegivenviatimecodemarkerswithrelatedcommentsand
informationviewableintheFORKMAMclient.
Anygeneralfeedbackorcommentsrelatingtothewholeoftheprogrammewillbe
attachedtoatimecodemarkerlocatedatthestartoftheprogrammematerial
(10:00:00:00)
TheprogrammemakerswillbenotifiediftheirprogrammehaspassedorfailedQC.
IftheprogrammehaspassedQCthenthevideofilewillbemovedintothePassed
QCbinfordeliveryuse.
IftheprogrammedoesnotpassQCthenthevideofilewillbemovedintotheFailed
QCbinandifrecentlyfaileditwillalsoappearintheRecentQCFailsbin.The
programmewillhavetoberesubmittedbyrepeatingthesubmissionprocess.
6.6SubmissionDates
Itishighlyrecommendedtoprogrammemakersthattheysubmittheirprogrammes
assoonaspossibletoallowtimeforfurtherpostproductionandresubmissioninthe
eventthattheprogrammedoesnotpassQC.
16/04/12QCProcessBegins
ProgrammesalreadysubmittedforQCandanysubmissionsreceivedafterthisdate
willberunthroughtheQCprocess.
21/05/2012-FinalSubmissionDeadlineAnyversion1submissionssentafterthis
deadlinecannotbeQualityControlled.Earlysubmissionswillbegivenpriority.
01/06/2012-FinalRe-SubmissionDeadlineAnyversions2orhighersubmitted
afterthisdeadlinecannotbeQualityControlled.
AnyprogrammesreceivedafterthisdatewillnotberunthroughtheQCprocessand
thereforewillnotbeusedforbroadcast.
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AppendixA
3.4.1AspectAreaandSafetyAreas
Belowisasimplediagramexplainingthe14:9safetyareaforaHD16:9programme.
3.1ITU-RBT.709-5
ThefollowinglinkgivesagoodunderstandingofthestandardsforHDprogrammes:
http://en.wikipedia.org/wiki/Rec._709
3.4.2Timecodeinformation
Pleaseclickonthefollowinglinkformoreinformationabouttimecodes
http://www.alpermann-velte.com/faq_e/e_atc.html
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4.2.2AudioLevels
Pleaseclickonthefollowinglinkformoreinformationaboutaudiolevels
http://www.blitzfamily.eclipse.co.uk/paulblitz.co.uk/tech_tips/techtip/art5.htm
3.2.2AudioandVideoErrors
OverExposure-overexposurereferstoawhite-lookingorwashed-outimage
(overexposedimage).ThisgenerallyhappenswhenaVideowasshotwithtoomuch
lightonthesubject.Thisoccurswhenshootingwiththewrongcamerasettings.
UnderExposure-whenimportantdarkareasare"muddy"orindistinguishablefrom
black,knownas"blockedupshadows"(orsometimes"crushedshadows,""crushed
blacks,"or"clippedblacks,"especiallyinvideo).
VideoexampleofUnderandOverExposure:http://vimeo.com/8752442
Saturation,sometimescalledchroma,dealswiththestrengthorpurityofacolour.
Saturationrepresentstheamountofgreyinproportiontothehue.Valuesrange
from-100(percentageofdesaturation,dullercolours)to+100(percentageof
saturationincrease).Onthestandardcolourwheel,saturationincreasesfromthe
centretotheedge.TheSaturationfilterletsyouadjustthesaturationoftheentire
image.
Crushing.Theartefactthatoccurswhenthepedestal(alsocalledtheblacklevel)is
adjustedtoolowduringtheshootingorreproductionofanimage.Crushingtendsto
reducecontrastindarkelementsofanimage.
SoftFocus.Awayoffilmingthingssothattheedgesoftheobjectsinthevideoare
notsharporclear.
LowContrast
LowcontrastmeanstherangeofDark----->Lightisverysmall.Meaning,maybeallthetonesaregrey.Nowhites,noblacks.Or,maybeallthetonesareverydark.
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Maybethelightestthinginthephotoisadarkgrey,andmostoftherestofblack.
Thoseareexamplesoflowcontrast.
VideoNoise
Theleftimageisclearlysufferingforavideonoiseerror,thistypeoferrorwill
dramaticallyreduceaprogrammespicturequalityandfailQualityControl.Though
thisismorecommonlyananaloguevideoerroritwillpresentitselfindigitalvideoin
theformofpicturesnow.
MixedLighting
Lightingisveryimportantforanyprogramme,lightingcanchangeorsetthemoodofasceneorevengiveyourprogrammeadistinctivelookbutitcanalsoruina
productionthroughinconsistentlightingarrangements.
Thefollowingpictureshowshowevenwithmultiplelightsourcesanimagecanstill
lookcold(blue)andgrainy.
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Itisimportantthatallofshotswithinaprogrammehaveasimilarlookandfeel,this
isachievedthroughlightingandbecomestrickywhendealingwithmultipleinternal
andexternallocations.Pleasetaketimeandconsideryourlightingarrangement
whensettinguptoshootatanylocation.
Vignetting
In video vignetting is a reduction of an image's brightness or saturation at the
image edges compared to the image centre.