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What's going on with the gamma?
Posted: Tue Nov 27, 2007 2:28 am
by superbad
My monitor gamma is set to 2.2. I am running a render with the gamma setting at 2.2. Check out this screenshot. The image on the left is what mxcl is displaying during the render, the one on the right is the version it saved at the last SL. Why does the saved version have a higher gamma?
I never noticed this in 1.5, but I can't say for sure it wasn't happening then too.
Posted: Tue Nov 27, 2007 10:17 am
by nachob
We are not saving files using monitor calibration, it is using standard RGB color profile. The problem of saving with monitor calibration is that it can give you different output in different machines or with different monitors.
nachob
Posted: Tue Nov 27, 2007 11:23 am
by tom
Maxwell applies 2.2 inverse gamma on input and corrects it back with 2.2, so the image you view in Maxwell viewer is correct. It looks like your image viewer on the right is applying a preview gamma to the images without gamma information.
Posted: Tue Nov 27, 2007 6:43 pm
by superbad
What should I do then? I want the saved images to look like they do in the MXCL preview window.
Posted: Tue Nov 27, 2007 7:59 pm
by tom
It's about your viewer, not the image. When you open it up in Photoshop or on another computer, what do you see?
Posted: Tue Nov 27, 2007 8:50 pm
by superbad
You're right- the Mac Preview application puts some kind of color profile on it, as does Safari. Annoying, and I can't seem to disable it. This is a calibrated monitor, so I don't know why OSX insists on messing with things. Anyway, it's fine in Firefox, as well as PhotoPaint, which I normally use for image editing on my Windows box.
Posted: Tue Nov 27, 2007 9:34 pm
by mgroeteke
your profile in OSX system preferences/ displays is always set to a display profile. check what profile is activated. best idea is to calibrate your monitor, anyway.
cheers
markus
Posted: Wed Nov 28, 2007 1:09 am
by superbad
Yep, it's calibrated, and the calibration profile is selected. If you go into preferences in Preview, there's an option for "Preferred CMM" under color, and this is set to Apple CMM and seemingly can't be changed (there's an option called Automatic, but it always gets changed back if you try to use it). As far as I can tell, it's only Preview and Safari that are displaying my renders differently than everything else. No big deal I guess, I just won't use Preview.
Posted: Wed Nov 28, 2007 11:41 pm
by Martti
The Color profiles is the endless jungle. I always convert my images to "Generic RGB"-profiles in Photoshop, if I want to be sure, it looks great also in PC, Safari, Preview ...ect.
Here is something to read:
http://developer.apple.com/qa/qa2004/qa1396.html
