Has anyone seen this before: I open a RAW file in PS. I convert it from aRGB (my working space) to LAB. As soon as I do this, it gets a *lot* redder. When I convert back to RGB, it gets a lot less red. I don't know what's going on.
You should not be getting any visible color shift on screen for simply converting to L*a*b. I can't come up with a single scenario that gives you a color shift with a simple conversion. The only way you should be able to get a shift would be to assign the wrong RGB profile to your RGB file, but you can't assign anything but RGB to RGB. Your monitor profile would have no impact on that, as, even it's it's not right, you're still using the same one for viewing. Have you tried resetting your preferences or tried this on a different computer? Does this happen when you convert to a different RGB space? Are you using a simple Mode Change or are you using Convert to Profile?
And, by the way, yes, there are many valid reasons for using L*a*b color. It's perhaps the most powerful color space to work in, but requires a completely different mindset to be proficient. Not right for everything, but when it is right, nothing else will come close. The trick, obviously is in knowing when to use it.
Thanks. I fully understand the benefits of working in Lab and have done so for many years. I never see more than a very subtle color shift when I convert to Lab. Something seems to be wrong with my color settings. My OS is Windows Vista.
You should not be getting any visible color shift on screen for simply converting to L*a*b. I can't come up with a single scenario that gives you a color shift with a simple conversion. The only way you should be able to get a shift would be to assign the wrong RGB profile to your RGB file, but you can't assign anything but RGB to RGB. Your monitor profile would have no impact on that, as, even it's it's not right, you're still using the same one for viewing. Have you tried resetting your preferences or tried this on a different computer? Does this happen when you convert to a different RGB space? Are you using a simple Mode Change or are you using Convert to Profile? ...Show more →
I agree that this is a bizarre behavior. I'm not assigning the wrong profile. The only think I can imagine is that I'm somehow implicitly changing the monitor profile. I have not tried to reset my preferences. I'm not sure what that'd mean. Converting between sRGB and aRGB creates no color shift. However, converting to L*a*b does, whether I use Edit>Convert or Image>Mode. It is really weird. It's also causing me a real headache because I use L*a*b routinely for color balance mods.
I did have a problem a few weeks ago where colors as displays in Canon Raw shifted when I opened an image in Photoshop. It was a Windows color management problem, resolved by setting some obscure option in Wondows>Control Panel>Color. I imagine that I'm having the same sort of problem here, but I just can't figure it out. (And I have no idea how my color settings got messed up in the first place -- real bummer.)
Can you double-check in your Color Settings that Ps is actually using the same monitor profile for both renderings. There's no way that it should change with a simple mode change, but at least you could eliminate one variable.
Your view "through the keyhole" into whatever working space you select is the color management's relative colorimetric reworking of the working space Lab coordinates to fit your your monitor's profile Lab boundaries. The screen view shouldn't change with the mode switch to Lab, except in soft proofing mode, and the fact it does seems to indicate the rendering to screen gamut isn't working.
Thus the #1 suspect would be what Peter has suggested. Something in PS preferences or on the OS level may be causing frigggin' in the riggin' with respect to how the monitor profile is being applied. You might also want to try selecting a different CMM in color preferences and see if that makes any difference in the results.
What was the last settings you remember changing on the computer / PS before the problem started? Have you recalibrated the monitor recently?
