Ongoing Gamma mismatch issue

[bobbystone]

Hey all,

I'm still having problems with my rendered Pro_res clips not matching the grade applied in RCX. Anyone else having these problems? The Gamma on the rendered movies are flatter and the saturation is less (which also might just be bcause of the gamma) But they don't look much at all like the files I'm grading. I'm attaching a side by side screenshot. On the left is the RCX window, and on the right is the rendered prores movie in the final cut viewer window. Note that if I render to a jpeg still, the gamma matches perfectly, so it's some sort of quicktime issue. It's a real problem for me though, so I'd appreciate a: knowing if anyone else is experiencing this, and B: if anyone has any tips or solutions:

Camera build 30.5.0
RedCine-X Build 262 for Mac
OSX 10.6.4
Quicktime 7.6.6
Redcode 4.0

[bobbystone]

Here's a sample fo RCX to jpeg. There are some subtle colro differences, but it's a MUCH closer match.

And on experimenting, it seems to be more like a black-point type of issue as opposed to a gamma issue.

[Aaron Hucker]

I am also getting this issue.. Hitting space bar on a mac to preview a file, its super washed, no contrast or saturation, open in quicktime, much better, but not a match to what I see in RCX... Love to find out the solution to get a better match.

[Graeme Nattress]

Ok - following up on this....

I have some reference R3D files I use in calibration. I know them well and their reference RGB values covering the whole the camera can produce. I loaded it up into RC-X, sent out a ProRes422(HQ), enabled chroma filtering for 444 sources, gamma correction of none.

In FCP I've loaded in the ProRes. I went through the reference values, comparing them between RC-X (ISO800, 2800k, REDColor, REDGamma) and the FCP output, using the digital color meter app to read out the RGB values. They match.

Also, reading above about the potential of it being a black point issue - I've checked the black levels of my clip in RC-X and in FCP (ProRes from RC-X) and they are identical.

So - the good news, it should all work just great. The bad news is that it's not doing so for you. That means there must be some setting somewhere that's not the same as what I have here. If we can figure that out, I think we'll solve this for you.

Graeme

[mikeburton]

Is your QuickTime settings set to enable FCP gamma? If not this could be your issue. QuickTime is looking at 1.8 gamma and RS-X is 2.2. Seems like this issue is pretty common.

[Graeme Nattress]

Thanks Mike - my settings in Quicktime are to enable FCP gamma BTW.

Graeme

[bobbystone]

Graeme, Thanks so much for looking into this for me. It's been a real bear to try to solve and a hindrance to my use of the camera. Is there some componenet or addition I may have that might cause a problem here? I do have 2.2 gamma checked in QT Preferences. Whats a simple way to start from the beginning to try to diagnose this?

Here's a screenshot of the gamma curve I've trial and error'd to try to get the footage to look proper:

[Graeme Nattress]

Can you check what the Quicktime export dialogue box has for it's gamma setting for ProRes inside RC-X?

Graeme

[Johnny Friday]

I've been looking into this issue for about a year now. It's gotten MUCH better with then new REDCODE QT component 4.2 which is in the FCP3 download on RED's support site. This may or may not assit you with getting gamma to match, but it seems that i was getting 75% matches with transcoding to prores from R3d's last year and up to date i'm getting about 90% or so.
That said....there may be multiple reasons and places to look. first off I'd look at what version of FCP suite you'r running. then if it's the latest, you might look into this:
http://reduser.net/forum/showthread....nsfer+problems

You'll need to manually delete fils within your library AND then go back and run the RED's update for FCP3. there you'll get the latest QT component update of i believe 4.2 which i believe assists with this undersaturated problem---at least it did for me. I posted on this many times only to be told it was a QT issue, but reality is that i don't think it was....I believe it was an issue with QT reading data with all of RED's FLUT, REDGAMMA, REDCOLOR etc.....and not reading it properly. Anyway, seems it's much better now after i went through maual deletion of files and reinstall of FCP3. It updated the new QT component from 4.0 to 4.2.

Try that to at least eliminate the obvious and get updated to the lates QT Component, then you'll at least be on better ground to move forward.

ARe you grading on a RR card or only on desktop? this makes a difference as well. and then to what monitor if RR out?

[Johnny Friday]

Can you check what the Quicktime export dialogue box has for it's gamma setting for ProRes inside RC-X?

Graeme

where exactly are you referring to Grame? within Export and then the presets? or another location?