twelve significant photographs in any one year is a good crop. - ansel adams · 2020. 8. 29. · -...
TRANSCRIPT
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