Color

Introduc)ontoDigitalPhotography

Twelvesignificantphotographsinanyoneyearisagoodcrop.-AnselAdams

Lectureoutline•  Howweseecolor– Addi)ve(RGB)/Subtrac)ve(CMYK)

•  HSB– Hue–  Satura)on–  Brightness(Luminosity)

•  ColorSpace–  ProPhoto– AdobeRGB–  sRGB– Whichonetouse?

•  Colortemperature

HowWeSeeColor

•  Re)na–  Cones

•  Shortwavelength(blue)•  Middlewavelength(green)•  Longwavelength(red)

•  Humaneye:–  10Millioncolorrange

•  Digitalcamera:–  Colorspaceweselect

hQp://upload.wikimedia.org/wikipedia/commons/thumb/0/04/Cone-fundamentals-with-srgb-spectrum.svg/540px-Cone-fundamentals-with-srgb-spectrum.svg.png

HowWeSeeColor

•  Color=reflectedlightthatisnotabsorbedbytheobject

hQp://appleadayproject.files.wordpress.com/2011/03/apple-full2.jpg

HowWeSeeColor1Millioncolors(actualsize:1000x1000px)

hQp://en.wikipedia.org/wiki/File:1Mcolors.png

Addi)ve(rgb)/Subtrac)ve(cmyk)

•  Addi)vecolor–  lightinavacuum–  red+green+blue=white

hQp://upload.wikimedia.org/wikipedia/commons/thumb/c/c2/Addi)veColor.svg/500px-Addi)veColor.svg.png

subtrac)vecolors

Addi)ve(rgb)/Subtrac)ve(cmyk)

•  Subtrac)vecolor–  inkonpaper–  yellow+cyan+magenta=purple-gray

hQp://upload.wikimedia.org/wikipedia/commons/thumb/1/19/Subtrac)veColor.svg/500px-Subtrac)veColor.svg.png

addi)vecolors

Addi)ve(rgb)/Subtrac)ve(cmyk)

•  RGB/CMYKcolorspace–  RGBbrighterthanCMYK–  RGB=transmiQedlight–  CMYK=reflectedlight

hQp://en.wikipedia.org/wiki/File:RGB_and_CMYK_comparison.png

Hue/Satura3on/Brightness

•  Hue–  colorvaluebetween0°–359°

•  Satura)on–  amountofcolor–  lesssatura)on=lightercolor

•  Brightness–  luminosityorvalue–  lessbrightness=darkercolor

MunsellColorSpace

ColorSpace•  Mathema)callydefinedcolorspace(Interna)onalCommissiononIllumina)on,1931)

•  Basedonvisualpercep)onofcolorbythehumaneye

•  Basisofcolorspaceusedindigitalphotography,Photoshop&Lightroom

hQp://upload.wikimedia.org/wikipedia/commons/5/52/Chroma)city_diagram_full.pdf

ProphotoColorSpace•  DevelopedbyKodak–  largestcolorspace–  hasimaginarycolorsthatexistoutsidevisiblecolorrange

–  abletomorefaithfullyreproducesaturatedreds,yellows,andorangesonhigh-endcolorprinters

–  na)vecolorspaceforAdobeLightroomandPhotoshop

hQp://en.wikipedia.org/wiki/File:Colorspace.png

AdobeRGBColorSpace•  DevelopedbyAdobe–  akaAdobeRGB(1998)–  designedtoencompassmostofcolorsavailabletoCMYKprinters

–  oneoftwocolorspacesavailableinmostcommercialdigitalcameras

–  na)vecolorspaceforolderversionsofPhotoshop

hQp://en.wikipedia.org/wiki/File:Colorspace.png

sRGBColorSpace•  StandardRGB(sRGBIEC61966-2.1)–  aka“small”RGB(or$h!QyRGB)

–  “small”=16.7millioncolors

–  smallestofnon-indexed(GIF)colorspaces

–  colorinkjetfriendlycolorspace

–  na)vecolorspaceforJPEGimages

hQp://en.wikipedia.org/wiki/File:Colorspace.png

WhichColorSpacetoUse?•  SizemaQers:biggerisbeQer–some)mes

•  Digitalcamerasshouldbesettolargestpossiblecolorspaceavailable

•  sRGBisusedforcomputerdisplays,web,visualmedia,andlow-end(fourcolor)inkjetprinters

hQp://en.wikipedia.org/wiki/File:Colorspace.png

ColorTemperature•  ColoralsohasatemperaturevaluebasedondegreesK(Kelvin)

•  BluecolorshaveahigherKtemperaturebutareseenascooler

•  RedcolorshavealowerKtemperaturebutareseenaswarmer

hQp://www.freestylephoto.biz/images/teacherslounge/colortempchart.jpg

ColorTemperature•  Somecommoncolortemperatures

•  Calibratedmonitors&LCDscreenshaveawhitepointofaround6500K

hQp://photographysquad.com/images/light.gif

ColorTemperature•  Colortemperaturecanalsobeequatedtowhitebalance

•  AdobeCameraRawallowsyoutoadjustwhitebalanceinpostprocessingsolongasyoushootRAWfiles

•  JPEGshavewhitebalanceencodedintofile,can’teasilychangeit

hQp://livedocs.adobe.com/en_US/Photoshop/10.0/images/sca_white_balance.png