Firstly, I would like to say that PhaseOne software is absolutely wonderful.
I´ve been checking colour accuracy with IT8 charts and blows out Gretagmacbeth,
Monaco, etc... Doro, you always know what I want. ;-) Thank you very much.
Wayne,
I´ll try to explain to you a little bit.
Why do we need colour management? First, human vision is represented with a CIE
chromacity chart. Sure you´ve seen it before.
http://www.efg2.com/Lab/Graphics/Colors/Chromaticity.htm
Inside this diagram you can find blackbody curve, device gamut and device white
point. You can find infinite white points in this blackbody curve. Each colour
space could have different white points and some of them are bigger or smaller
AdobeRGB > sRGB. So, how could you convert from one to another. If you cannot
find one colour in one gamut due to is much smaller you shoud convert all
colours trying to simulate the whole appearance. Sure, you´ve seen PERCEPTUAL
mode. Convert from AdobeRGB1998 to sRGB using perceptual mode. You must be very
careful if you are working in AdobeRGB, adjusting levels to increase contrast
and broadening dynamic range and then you jump to srgb, you´ll see how much you
lose detail into the shadows and highlights!!! Try opening one E1 image in
ProPhotoCD gamut, have a look to histogram and then convert it to srgb! It´s
very important workpath! Opening one picture in gamma 1.0, apply unsharp mask
into this gamma, in order to avoid gamma induced error
s, then apply ICC profile, convert it to your desired gamut and finally adjust
levels and curves but never before.
What is gamma? Human vision response is near to gamma 2,2. CCDs, CMOS,
computers work much better with linear gamma but they must convert it to gamma
2,2 for displaying the information into the monitors.
What´s the difference between Adobe Photoshop RAW image plug-in and PhaseOne
software.
E1 raw image file is fully mapped into AdobeRGB, sRGB colour space and nothing
more in Adobe camera raw plug-in but PhaseONE creates a ICC profile first. They
measure how much colour deviation is produced in KODAK KAF-5101ce image sensor
using colour charts. So there is a E1 colour space defined into this CIE
chromacity chart (human vision). Each colour you can see is located into this
E1 space and now corrected! Now you can conver it to whatever colour space you
want. Hope this could help you.
Best regards,
Dave
pd: Forget about this annoying stuff and use PhaseONE software. It´s awesome!
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