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ProRes Gamma Shift
Hi there, sorry if this gets really confusing but I’m trying to understand how and why the gamma shifts are happening between AE and FCP using the ProRes Codec. This is only a problem with the ProRes codec as I do not receive any gamma shifts using Animation.
I have an original H264 file from the Canon 5D which I’ve converted to both ProRes and Animation. Obviously the Animation file is not practical to work with, but I’m just testing gamma shifts. After conversion in Compressor, all 3 files look identical in Quicktime. My monitor is set to 2.2 Gamma, and Quicktime is set to ‘Final Cut color compatibility’ 2.2 Gamma
First, when I bring the 3 files into AE, the Animation looks correct, the H264 and ProRes are dark. By switching the project to 16bit, the ProRes files looks correct and there is no shift in the Animation or H264 file.
The crazy thing is when I render the ProRes on 16bit the gamma is brighter than the original and when I render it on 8bit it looks correct!?!? So I can trust the image in AE on 16bit, but not the render and I can trust the render of the 8bit, but not the image in AE. And to top it all off, if I work and render the ProRes file in 16bit as Animation it looks correct, but if I render 8bit it’s really dark… what is going on with this codec?
This has lead to a really awkward workflow where I do all of the color correcting with the project set at 16bit and then render it at 8bit so I get proper results… it just doesn’t make sense.
After all of that, the gamma of my ProRes file in Quicktime does not match what I see in Final Cut, but the Animation does. I guess I’m answering my own question here by just sticking with Animation, but the workflow is just not practical. I’m sure this has something to do with YUV vs RGB, but why would one codec have a shift and the other not? Which Gamma should I be trusting, FCP or Quicktime?
If someone could point me in the right direction I would greatly appreciate it!
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6 Replies
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I experience gamma/color shifts when I ingest prores into AE and export to RGB(QT-Anim), but I don’t experience any problems going into AE with prores and exporting with prores.
Do you by any chance have any AJA codecs installed on your machine? In the past, an AJA codec has caused some strange problems with prores.
Finally, I’ve been working back and forth with a user and he’s been having gamma shifts in 16bpc and 32bpc, but not 8bpc. I’ve was never able to reproduce, but I emailed him my prores codec and his problem went away. My codec was bit for bit identical with his, so I’m not sure what happened there. Maybe a permissions issue? You could try copying your codec (library/Quicktime) to an external HD, then copying it back and replacing your original.
Also, Apple’s going to gamma 2.2 in Snow Leopard, so I’m interested to see which problems this solves and possibly creates.
Thanks,
Dan Ramirez
AE QA Engineer -
I do not get a gamma shift when switching between 8bpc and 16bpc in AE, but I have just been working with a customer who had the exact same problem. Like I mentioned before, I emailed him my prores codec and the problem went away for him. This is strange because our codecs were bit for bit identical. I was also unable to reproduce when I tried using his codec.
I suggest the following:
copy [your hard drive]/Library/Quicktime/AppleProRes422.component somewhere off your computer(external drive, email, CD, etc,). Delete the original, then copy the file right back to the same location.
If this doesn’t work, we can try something else.
Dan Ramirez
After Effects
QA Engineer -
I do have AJA I/O codecs installed, but on my MacPro at home I have the same problem with no AJA Codecs. So when you bring a ProRes file into AE and switch between 8bit and 16bit, you don’t see a gamma shift?
Thanks for the feedback!
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Hi Daniel, thanks for the input. I tried replacing the codec, it didn’t make a difference. I’ve removed all AJA components as well and that didn’t make a difference. I decided to run another quick test and came back with the same results. I took an Animation Compression clip with a photo and some graphic elements in it and brought it into After Effects, then rendered and viewed in Quicktime.
– Animation render as expected exact copy
– ProRes Render lighter gammaWhen I bring the ProRes render back into AE, the graphic elements of the image seemed to get pretty jaggy compared to the original and the gamma switches when I go from 8 bit to 16.
Any other suggestions?
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However, for RGB codecs, 2.2 is not often the correct value. This means that files that use RGB codecs (such as Animation or None) are over-corrected and look washed out or too light.
If you enable the Match Legacy After Effects QuickTime Gamma Adjustments option in the Project Settings in After Effects CS3, then it will not tag QuickTime files with the metadata tag when it renders them.
edit MediaCoreQTGammaRulesCS4.xml in C:\Documents and Settings\Robert\Application Data\Adobe\Common
so that your codecs are tagged or not with 2.2 gamma. If your codec fourcc code is not in there, AE will burn the wrong gamma flag into your output!!!
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In after effect try export via file menu instead of add render queue. If you check the project setting in file menu, you should see color profil, if its on, you can match legacy after effect quick gamma adjustement…, maybe it the problem…But if the color profile is off, and your color are set, let it off.There few problems between after effect and quick render engine that why you should try to “export” via export because it use quicktime renderer.
Hope its help
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