GAMMA LUT CORRECTION

New Here ,
Feb 03, 2021

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I'm working on a project and color graded my whole project and when I exported it it was turned into some other colors. It wasn't right so I trued to apply the gamma lut correction offered by adobe when exporting and it made my whole video turned black instead of fixing the colors. Can someone tell me why it is just not acting normal and color correct simply my videos?

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Editing, Error or problem, Export

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Adobe Community Professional ,
Feb 03, 2021

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Please post your:
Computer specs/setup,
Operating system build (not just the latest).
Premiere exact build (see about),
Mediainfo screenshot in treeview of media used.
And screenshots to how us what other colors you are talking about.

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New Here ,
Feb 03, 2021

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Mac Book Pro (13 inch, m1 , 2020)

Version 11.2 Mac OS Big Sur 

Apple M1 chip

I'm operating on 14.8 premiere pro

This is before I apply the Gamma correction LUT and after when I apply it it turns my video black. Instead of just adjsting the colors.

Screen Shot 2021-02-03 at 1.53.52 PM.png

 

Screen Shot 2021-02-03 at 1.53.55 PM.png

[Moderator note: please add images by drag/drop onto your reply box text area. Do not use the "attach files" process as that requires other users to download strange files to their computer to see them. Yea, stupid forum software ...  but I fixed this post for you.]

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Adobe Community Professional ,
Feb 03, 2021

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I do note that you have selected to apply an export LUT, but that screen-grab doesn't show any LUT actually selected and applied. Does that make a difference?

 

But first, understand that color management is a morass. It's bad enough everywhere, but then Apple didn't help when they went to the Retina screens with the P3 color primaries ... and created some odd choices in their ColorSync color management utility.

 

Premiere Pro works properly in a solid pro standard broadcast Rec.709, which is still the basic standard for nearly all video made. sRGB color primaries, Rec.709 "profile" including both the camera and display transform functions, D65 white point, gamma 2.4 (2.2 for "bright viewing conditions") and a screen white brightness of 100 nits.

 

Apple chose to do things uniquely Apple. So ... ColorSync applies the sRGB primaries, what they call "sRGB gamma" which by reverse engineering seems to be sorta between 1.95 and 1.96 kinda mostly; then they only apply the camera transform but not the also-required display transfrom ... and run at full screen brightness.

 

(Oddly enough, some iPads have some of the most correct color management out there ... huh.)

 

When they came out with this intriguing uniqueness, the Adobe engineers came up with the "Display color management" option, which tells Premiere to look at the monitor's ICC profile, and re-map the internally displayed images in an attempt to show a correct Rec.709 image. It works decently within Premiere.

 

But ... after export, of course ... that file is now displayed according to whatever system it's on ... and the predilections of browsers and players that all try to "enhance the viewing experience" by doing things you don't really want them to. And ... on a Mac, it means it looks typically lighter, especially in the shadows; the highlights are shown so bright they may look washed out also; the colors may or may not be remapped to closely match the hues seen within Premiere; and because of the generally brighter tonality from the lifted gamma, apparent saturation will be less.

 

So Adobe also produced that "gamma correction" export LUT so that you can mod the image on export so it looks mostly the same outside of Premiere on your Mac as it does inside Premiere.

 

However ... on any say PC, Android or other system not running the Mac ColorSync utility, it will be dark and over-saturated.

 

Davinci Resolve tried a different approach ... they have an export option called "Rec,709-A", and yes, the A is specifically for Apple. This adds a different NLC "tag" in the file header, so the Mac Colorsync utility actually applies both transforms and correct gamma. Wonderful!

 

But ... on many non-Mac systems, that still causes color management to apply things to ... make the file too dark and over-saturated.

 

Right.

 

This general color management mess may be the heart of the issue you are having ... and there ain't no perfect solution. I don't know how many colorists have struggled to find a way to create or 'tag' a file that would play correctly in Macs and everything else out there. No one has.

 

But then ... no matter what you create that file on, no one on the planet will ever see it exactly as it was on your screen. Not even if you're a top colorist with their setups. And understand, they spend more on calibration hardware/software than you've probably spend total. A proper "grade 1 reference monitor" starts around $5,000USD for SDR work, and if you're producing for b-cast/streamed HDR, that monitor is upwards of $17,000, probably around $30,000. And yea, I know a few people with those things.

 

Doesn't matter ... they produce to the standards, and then ... every screen out there shows it differently than what it was on their screen. But by producing it to the standards, they know ... that in relative terms, their material will look like all other pro produced material as it displays on any one screen.

 

That's about all you can do. Master you color managment, produce accordingly, and let it go out Into The Wild.

 

Neil

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