Luminance shift problem
by Rich Rubasch on Sep 22, 2005 at 7:27:51 pm
A while back there was a discussion about luminance shifiting when 10-bit clips were brought from final Cut to AE...basically the clips got brighter. It didn't seem to matter which I/O card users had.
Now I have exported a DVCPro50 reference clip from a DVCPro50 timeline to fix a cord in the shot. Sure enough it looked birghter than the orig. I exported a self contained animation clip of the same shot and it was a perfect match.
AE 6.5, FCP 4.5, QT 6.5.3, Pipe Studio card, G4 Dual 1-gig, OS 10.3.9.
Anyone having this with Tiger and QT7 and the Pipe card (or other card).
I have had this on certain clips from AE renders. I even had it hapen to me on an animation clip but I later figured it was my BG color inthe comp.
I think sticking to the annimation codec is the best way to go. This is the "stock" codec for livetype and other stuff. You could maybe place a levels filter on the compositions before the final render and bring the blacks to zero and the whites to 235 to force teh movie into the color space you are working in.
Re: Luminance shift problem by Cofe on Sep 22, 2005 at 9:02:06 pm
yes I had this with the Pipe and Qt7.01. You're right this is/was a QT problem not a specific card problem as I read numerous post on the blackmagic forum about this as well.
Now i think it has finally disappeared in QT7.0.2. I say 'I think' as I hadn't ahd the chance the fully test it with all QT software and all codec combination. But 2 days ago I did some test where I needed motion tracking and exported DV codec and rendered into DV again and no problem! (I think it is a YUV-RGB-YUV QT problem rather then a specific codec problem?)
Strange thing is that I can't find any release notes for QT7.02 which would confirm the change?? Also strange is that Apple released a re-installer for 7.01, which only means that some big shots had serious problems with 7.02??
Need to do more testing..
Re: Luminance shift problem by Cofe on Sep 26, 2005 at 7:25:27 am
I just tried the Aurora Uncompressed codecs with FCP-AE and same result in Tiger/QT7.0.2.
The way to compensate is to apply around 1.2 Gamma level shift in AE to the ref clip from FCP.
I did read about this somewhere but unfortunately forgotton where it was :-(
I will drop a line to Aurora and see if they can clarify the issue.