Author Topic: Another color space question  (Read 3801 times)

Offline courtlevephoto

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Another color space question
« on: March 31, 2009, 10:15:14 AM »
I am on a mac and use PM and Lightroom. I do my edits in LR and my viewing in pm(MUCH faster).

Anyway, I'm having issues seeing the same colors from one program to another. I understand that Lightroom uses ProPhoto rgb when viewing. I edit a raw file(nef) and covert to .dng. At this point I can see my edits in PM. However the images are showing me that the color space (icc) is sRGB, not rgb or prophoto. My assumption is that the .dng file I'm reading is nothing more than the built-in preview, that for some reason defaults to sRGB.

So, a couple questions.

1. Should PM be set to sRGB or prophoto?
2. When I turn off color mgmnt what color space am I seeing?
3. Should I turn on or off color mgmnt in PM

thanks.

Offline Hayo Baan

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Re: Another color space question
« Reply #1 on: March 31, 2009, 01:33:08 PM »
As I don't use dng, I don't have a clue as to what it does with the colour space of the (embedded?) JPG.
What I do know, however, is that you should normally leave PM's colour management ON (the only advantage of turning colour management off is speed).

Kirk'll probably have the answers to the other parts of your questions.
Hayo Baan - Photography
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Offline rjp

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Re: Another color space question
« Reply #2 on: March 31, 2009, 03:10:20 PM »
As I don't use dng, I don't have a clue as to what it does with the colour space of the (embedded?) JPG.
What I do know, however, is that you should normally leave PM's colour management ON (the only advantage of turning colour management off is speed).

Kirk'll probably have the answers to the other parts of your questions.

If you leave color management off what colorspace is used?

I was under the impression it was the default (in my case sRGB), so I've been leaving color management off thinking it helps me see how the images will look when ultimately viewed in sRGB, which is my goal. If I accidentally get an Adobe RGB image in there it looks washed out if color management is off, which I like because it alerts me that something is wrong.


Offline dennis

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Re: Another color space question
« Reply #3 on: March 31, 2009, 03:24:34 PM »
Well of course RAW files don't have a full color profile until they are rendered into something like RGB, and then depending on the gamma, white point, and chromaticities used you have an RGB color space which could be AdobeRGB, BruceRGB, or ProPhoto etc.

The previews in DNG files are assumed to be sRGB and that is what PM is showing.  But if you use color management in PM (which is recommended) then the previews should pretty much match what you see in LR (for colors within the sRGB gamut).  I doubt your monitor is capable of displaying the full gamut of ProPhoto RGB (some are calibrated for the "smaller" AdobeRGB gamut) so what you are seeing in LR is already clipped.

--dennis


Offline dennis

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Re: Another color space question
« Reply #4 on: March 31, 2009, 03:34:51 PM »
If you leave color management off what colorspace is used?

I was under the impression it was the default (in my case sRGB), so I've been leaving color management off thinking it helps me see how the images will look when ultimately viewed in sRGB, which is my goal. If I accidentally get an Adobe RGB image in there it looks washed out if color management is off, which I like because it alerts me that something is wrong.

If color management is turned off then the RGB values are sent directly to the monitor (i.e. they are unmanaged) which will give unpredictable results.  Some people turn this off to get an extra speed boost but I wouldn't recommend that.  There are other specialized reasons for turning off color management, e.g. if your photos are all AdobeRGB then you can turn off color management and get a screen capture and assign the color space of AdobeRGB to the screen capture - better than compressing AdobeRGB to your monitor's color space before a screen capture then expanding again when saving as, say, sRGB.

Just because your default is sRGB doesn't mean there is something wrong with an AdobeRGB photo per se, other than software such as some web browsers which assume sRGB.

--dennis