Stay ColorSunc

I have a 30” Cinema Display attached to my 17” MacBook Pro, and often when I return to the computer after the screensaver has kicked in, I find that my display has reverted to some default ColorSync setting rather than my calibrated, gamma 2.2 profile. The visual effect is that the screen is brighter and bluer than I’d left it.

You can fix this manually by opening the Displays section of System Preferences. This little ritual has gotten quite old though, and it finally occurred to me to do some Googling. I found this helpful blog entry that suggested the following Terminal entries:

cd /Library/ColorSync/Profiles/Displays

sudo chmod 664 *

(Standard disclaimers apply any time you use the terminal, execute the sudo command, and go outside on a sunny day.)

This didn’t work for me until I also changed the permissions on the Displays directory (and the other profiles in the Profiles directory too for good measure):

cd ../

sudo chmod 664 *

So far so good—I appear to be free from the forces that seek to revert me to -blech- gamma 1.8 land.

Whenever I encounter weirdness with Apple OSs or apps, I try to report them at apple.com/feedback. Who knows if it helps, but almost all the issues I reported about my iPhone became fixes in later firmware revisions.

(Oh, and of course I realize that I could just turn the screensaver off, but I tend to leave it on with password verifications for security reasons.)

Comments

[Nek]

Thanks for the tip Stu. Because I don't do anything particularly colour sensitive I keep it on adobe RGB 1998 with no calibration and it seems to stick past the screensaver.

And more people should use the feedback form, I've had more than a few suggestions I've made show up in releases.

[Casey Pegram]

Stu, do you use a 2.2 gamma even inside Final Cut? I was under the impression that FCP is already doing an internal gamma conversion of some sort and that running 2.2 on top of it just makes things overly dark. Can you clarify whether this is the case, and if it applies to any other pro apps?

I guess if you're taking the Rebel approach and grading in AE it's kind of a moot point...

[johnmontfxguide]

Man -- how timely. Thanks for the share.

This was killing me just this weekend!

[Franz]

Thanks for this. Like casey, I would love to hear your thoughts on display calibration for FCP work--particularly in the case when a monitor is not available.

-Tom

[mattsand2000]

fcp doesn't do anything, it's the codec. most apple codecs "correct" the gamma to look right on 1.8. if you're using blackmagic codecs or whatever you get the native gamma. it's the same in after effects by the way.

[Thom Steinhoff]

Stu,

Like others I would really like your advice on 2.2 gamma with Final Cut. As a Red user, I was told to calibrate my monitor to 2.2 "or else" and everything works well, until I try to play it somewhere else (like Apple TV) where everything is washed out. I'm trying to get software to strip the gamma tag--maybe that would help--but it shouldn't be this difficult!

By the way--I loved your book and recommend it often!

Best Regards,

Thom

[Ben Lam]

Hey Stu,

I'm wondering if the permission change to the Profiles directory did the trick in preventing the blue tinge / gamma revert from happening? That might have been the missing step that I never figured out. I thought the permissions change to the color profiles themselves would fix the problem (hence my blog post that you've linked to), but after a few days I noticed the blue tinge appearing again.

I ended up (for unrelated reasons) simply having the display sleep before a screen saver would start, the side effect being no more blue tinge on waking from a screen saver. And since I'm using a LED backlit MacBook Pro, there's no annoying warm-up time on the display either.