Gamma shift in Color? the solution...

[Ivan Cortazar]

Here the correct way.

MXO2 with Color, if you are grading R3D, apply 0.810810 to the master gamma while you grade, then upon rendering to DPX, take this away. If you are rendering to YUV QT then burn that master gamma in, so keep the 0.810810 value then render.

Sorry about the mistake.

Great!, Thanks a lot Kaku, now the whole world makes sense!! Finally I understand it. I also made a DVD and it is pretty much the same as the MXO2 monitor. A bit darker, but that could be the TV set or the Mpeg2 encoding. I'm in no close situation to have a perfect color grading station, but it feels good to know at least what to expect and how to adjust if needed.

arty:

 

[Ivan Cortazar]

Same here, even with the recent version. Very unstable in 4K.

yes it is very unfortunate. If you apply a lot of filters, well, then it is a who knows what will happen when render.

I got the paranoid syndrome of clicking coomand+S every minute.

I have also got a small script to allow render in the background and allow me to keep working with AE. Pretty neat.

 

[Kaku Ito]

Great!, Thanks a lot Kaku, now the whole world makes sense!! Finally I understand it. I also made a DVD and it is pretty much the same as the MXO2 monitor. A bit darker, but that could be the TV set or the Mpeg2 encoding. I'm in no close situation to have a perfect color grading station, but it feels good to know at least what to expect and how to adjust if needed.

arty:

Good, good. If you want to see if your mpeg2 on the DVD is correct, what you can do is to rip it on Mpeg Stream Clip to convert it to uncompressed SD, then place it on the FCP timeline, so you can see on the MXO2. HD is 709 and SD is 601, so might not be exactly the same because of the luminance level difference (anyone can elaborate this?).

 

[Ivan Cortazar]

Good, good. If you want to see if your mpeg2 on the DVD is correct, what you can do is to rip it on Mpeg Stream Clip to convert it to uncompressed SD, then place it on the FCP timeline, so you can see on the MXO2. HD is 709 and SD is 601, so might not be exactly the same because of the luminance level difference (anyone can elaborate this?).

That's a great idea. But now that I started to be happy, there is a 601 variable I wasn't aware of? :crying:

So if 709 is more or less gamma 2.2 what's 601? Is it same gamma but different luminance? Well, another variable. And if we add, inches-km, pounds-kg and driving on the left or on the right, the world is a chaos. And now that we thought Blu-ray was the only one, we'll have Red-ray.

Ahhh.



Ivan C.

 

[Kaku Ito]

I pretty much started video after HD, so not certain. Gamma is probably the same. Maybe just the color reproduction is different.

 

[Paul Lee]

Evangelos or any other color science gurus out there...
We have noticed some odd behavior when working on RED footage directly in Color: if, for whatever reason, our Colorist disables the RED tab in Primaries, the rendered media in FCP has a dramatic amount of contrast, well out of 100 and below zero, only on the rendered media. Oddly, we don't see it while rendering (Kona 3 updating the screen), but all hell breaks loose when we g back to Color.

Any ideas other than 'don't disable the RED tab?'

 

[Evangelos Achillopoulos]

Evangelos or any other color science gurus out there...
We have noticed some odd behavior when working on RED footage directly in Color: if, for whatever reason, our Colorist disables the RED tab in Primaries, the rendered media in FCP has a dramatic amount of contrast, well out of 100 and below zero, only on the rendered media. Oddly, we don't see it while rendering (Kona 3 updating the screen), but all hell breaks loose when we g back to Color.

Any ideas other than 'don't disable the RED tab?'

I don't get it... how you work with R3D's with the RED tab disabled?

 

[Paul Lee]

Yes, I realize this sounds odd. If you disable the tab, Color is still working with the footage just fine, but you don't have control over the metadata any more. We see slightly higher detail in the highlights when we run with the tab disabled and do our base correction in the primaries room. Enable the tab, and no amount of fussing with exposure, ASA, contrast ,etc. in the tab will give us the full latitude into highlights we see when the tab is disabled. But when we render with the tab disabled, the contrast get jacked way up with whites hitting around 108 IRE and blacks very crushed at 0. Crazy, yes?

We are on most current build of Color and footage is RED v17 shot 4K 2:1.

 

[Evangelos Achillopoulos]

I have been informed by Meryem Ersoz that the FCP.mga was missing...

I just put it back... in the first post...

 

[bandry]

Looking for a fix to an earlier mistake

Looking for a fix to an earlier mistake

Hi everyone. I made a mistake of not reading through as many threads as I should have about color timing in Color and now I have already rendered out of Color to uncompressed 8 bit quicktimes (which viewed in quicktime look the way they are supposed to), without color correcting with a gamma shift appalied and than taken off before rendering, as I have learned I should have done after reading all day about my problem of sending back to FCP and the footage looking too dark and contrasty.

I am wondering if anyone has a quick fix for me, as I will be outputting from Color again later (as in a week or two from now), but I do need to burn of DVD tomorrow from the renders I have already done.

I have tested a gamma shift in FCP or in compressor to compensate and it looks pretty good, but not as good as I think it should.

Any ideas?

Thanks

 

[Kaku Ito]

The quick fix would be apply gamma adjustment. Probably your clip is based on 1.8 gamma now, so apply either 1.222222 or 0.810810 (depending on the program).

 

[Nate Smith]

Hello all!

After reading through these posts and trying (partially successfully) to understand them, I've pared it down to the following workflow:

-Grade normally in Color with no LUT
-Before rendering, import the LUT and change master gamma on the clips to 1.22
-Render with the LUT and the higher gamma
-Send to Final Cut, Export Quicktime.

This gets me pretty close to the end result I'm seeing in Color..... but not quite. The end result is still a bit too dark. Have I missed a step or am I not quite getting something right?

I'm using ProRes 4444 codec, except uncompressed when rendering out of final cut. I don't have a proper broadcast monitor, and my Cinema Displays are calibrated properly to 2.2.

As a sidenote, when I export using ProRes 4444 codec out of FinalCut (even without doing any workarounds) the footage looks absolutely perfect. Problem is, as soon as I compress that to something viewable on, say, the web, the colours go far too dark.

Cheers!

 

[Ido Karilla]

Yes, I realize this sounds odd. If you disable the tab, Color is still working with the footage just fine, but you don't have control over the metadata any more. We see slightly higher detail in the highlights when we run with the tab disabled and do our base correction in the primaries room. Enable the tab, and no amount of fussing with exposure, ASA, contrast ,etc. in the tab will give us the full latitude into highlights we see when the tab is disabled. But when we render with the tab disabled, the contrast get jacked way up with whites hitting around 108 IRE and blacks very crushed at 0. Crazy, yes?

We are on most current build of Color and footage is RED v17 shot 4K 2:1.

Just a guess,
With the RED tab disabled you might be seeing REDRAW linear, so if I am not messing things up then you are watching gamma 1.0 on a monitor with gamma 2.2 while you are probably rendering in gamma 1.8\2.2 getting the result you all ready know.