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What colourspace are you using? Adobe RGB, SRGB or someting else

Started by CvanDijk, March 05, 2008, 12:19

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sharpshot


stokfoto

the topic seems a lot more confusing than it initially seemed  to me,but thanks for bringing this into attention.now I will have to have a second thought too.

leszek

It seems that indeed there is a lot of confusion going on.

To start with - very few monitors can actually reproduce AdobeRGB colors (some expensive Eizos can and maybe top of the line NEC Spectravision, there may be some more). Most monitors do well if they come close to reproducing sRGB.

When working in AdobeRGB, you do not see AdobeRGB colors - if they are out of the monitor gamut (but still within gamut for AdobeRGB).
Even when they are within sRGB gamut, the situation is the same, because the same (r,g,b) values in AdobeRGB and sRGB basically mean different colors - to the eye, or to a spectrophotometer.

At this point calibration and profiling of the monitor enters. Calibration being the proper setup of R,G and B guns , setting black and white points and color temperature. Profiling being setting up a LUT table to provide corrections between measured and expected colors on the screen. So - calibration and profiling are not the same thing, and are frequently mixed up. Let's assume at this point that our hardware is calibrated and profiled - in short, that it can reproduce sRGB space (or is close to it).

Now - assume that we work in AdobeRGB color space, in COLOR MANAGED application. The application still can't display full AdobeRGB gamut on the monitor - but it will make some intelligent (non-linear) mapping of colors into sRGB - because it KNOWS that the working color space is AdobeRGB. And these colors are displayed properly by our (calibrated and profiled) monitor. And all is good with the world.

Now - you post the file (AdobeRGB color space) on the net. The software which displays the file usually does not care about color space and assumes sRGB - which means that it treats the (r,g,b) numbers literally. No information is actually lost - just is interpreted in a simple way. You may end up with washed out colors and color shifts.

When, however, the file is CONVERTED from AdobeRGB to sRGB prior to uploading - the "intelligent" treatment of the AdobeRGB colors by the color aware application is preserved - because in the process of converting, the (r,g,b) numbers are actually changed -  as compared to the original AdobeRGB file.  At this point one only hopes that the monitor used for display, somewhere in the world, is actually calibrated and profiled. In which case someone will see an image pretty similiar to what you intended him to see.

In essence - work in AdobeRGB, and CONVERT to sRGB before uploading. Uploading AdobeRGB file is usually a recipe for misinterpretation. If sRGB file is uploaded - all the user needs is to have his monitor calibrated and (hopefully) profiled.


I hope that by posting this lengthy explanation I haven't added to the confusion  ;D

null

Quote from: The Corey on March 06, 2008, 07:11Generally it is better to work with files and formats that give you the most amount of data headroom. Hence RAW converted to uncompressed Tiffs or PSD files, 16bit, Adobe 1998 or even better Pro Photo RGB. (Storage is cheap ).

So we develop RAW like this?


But then? Convert to jpg/sRGB to upload to agency sites?

vonkara

Quote from: FlemishDreams on March 07, 2008, 18:50
Quote from: The Corey on March 06, 2008, 07:11Generally it is better to work with files and formats that give you the most amount of data headroom. Hence RAW converted to uncompressed Tiffs or PSD files, 16bit, Adobe 1998 or even better Pro Photo RGB. (Storage is cheap ).

So we develop RAW like this?


But then? Convert to jpg/sRGB to upload to agency sites?
Could you tell me what is this software screen shot (PS CS2 CS3?)... actually I want work in adobe RGB but I don't have this option in my version.!?

null

Quote from: Vonkara on March 07, 2008, 20:51Could you tell me what is this software screen shot (PS CS2 CS3?)... actually I want work in adobe RGB but I don't have this option in my version.!?
It is from the Nikon Raw developer. I had this thing last year but never managed to install it since Nikon knows how to make cams but their software sucks. I got a new laptop a couple of weeks ago and no way to escape Vista. When I reinstalled my Photoshop CS2 and updated it online, the Nikon raw developer was suddenly there in its full (paying) version.

So this screenshot is from the Nikon raw developer plugin in Photoshop.

stokfoto