QT Gamma Compensation LUT

[NickiDoane]

Hi There, 

Months ago I found a download here I think for the QT Gamma Compensation LUT ... I just updated my mac and now the file is a .cube and I don't know how to change it to a usable file again. Help? Does anyone know where I can find the file again to download & use?

[NickiDoane]

Nevermind having a moment - it's fine.

[chrisw44157881]

i am not aware that the lut doesn't work with mac. premiere reads the file so it should still work.

download lut here:

https://community.adobe.com/t5/premiere-pro-discussions/quot-why-does-my-footage-look-darker-in-prem...

just place it in location here:

https://community.adobe.com/t5/premiere-pro-discussions/faq-premiere-pro-lumetri-color-custom-lut-di...

and render out with lut.

[zensei24321378vihf]

Is this still a thing that needs to be done in July 2022 with latest Adobe?

[R Neil Haugen]

That of course, depends.

As the need ... or use of that LUT ... is caused by the Mac OS color management utility ColorSync applying a non-standard gamma to Rec.709 video files.ColorSync, for some reason, uses a 1.96 gamma.

So Rec.709/SDR video files are displayed with lighter shadows and mids on a Mac, than they would be if displayed with the "normal" Rec.709 gamma of 2.4.

Premiere always attempts to operate by the Rec.709 standards, including it's internal monitors which are not 'controlled' by ColorSync. So the image typically is darker within Premiere than outside on the same Mac computer.

That LUT will essentially push the midtones and shadows a bit darker in the exported file, so that when viewed on a Mac, outside of Premiere, the file will look more like it did while viewed in Premiere.

But of course, then outside of the Mac-sphere, on a non-Mac system, that file will now be a lot darker than it appeared on the Mac within Premiere. Because on non-Mac gear, the Rec.709 video file will probably be displayed with a correct 2.4 gamma.

So ... the choice is between two imperfect things:

• A bit light on a Mac, but "normal" outside of Mac displays without the LUT.
• "Normal" viewed outside Premiere on a Mac, but too dark outside of the Macs.

That dilemma can't be "solved" by a version change with an outside app like Premiere or Resolve. The need/use of the LUT could only be changed by a change of the standard used by ColorSync.

Neil

[Aadnan26492056qqa9]

Could have made it easier for everyone uploading to youtube. Could have been a toggle and not a random file that's not even provided by premiere from the get go.

[R Neil Haugen]

True.That would have been a lot easier for the users.

Although ... when you apply that to a file, you do understand it's going to look a lot worse ... very dark/contrasty and over-saturated ... on all non-Mac screens, right? For example, if you have any scenes that are relatively dark to begin with, the shadows will simply crush.

Which is why my colorist buds ... mostly Mac people of course ... are furious with Apple over creating this problem.

Neil

[defaultqjtdlqoon3z5]

Dear Neil, 

We understand that you have strong convictions about the way you believe color space should be accomplished. However, we must consider the bigger picture and the fact that a much larger group is already working towards completing and editing videos in a certain way specifically for Apple products. It is important for us to work together and come to a compromise rather than insisting on doing things solely our own way.

While we respect your beliefs and opinions, it is a little bit selfish to insist on doing things only your way when there are so many other people involved in editing. By coming together and finding a solution that works for everyone, we can ensure that the task is completed efficiently and effectively.

From the thousands if not tens of thousands of people who edit video for devices, we urge you at adobe to consider the benefits of working together and compromising in order to accomplish meaningful this important task. We are the paying customer. Let's put aside our individual desires and focus on the greater good to fix this adobe color space issue so that exports look like the edits... It is time. It has been years.

[defaultqjtdlqoon3z5]

For anyone finding this forum. The fix listed above with the Gamma Correction Lut still does not accomplish the desired result of maintaining your color grading. If adobe can render a preview that is vivid it should be able to create an export that is vivid as well. 

[R Neil Haugen]

What a bizarre response ... let's review the situation.

The "normal" standard for Rec.709 is to apply the camera and display transforms. That is the regular & expected method in all pro broadcast applications.

Adobe applies that universal standard to the media.

Apple chooses to work differently, and does NOT apply the display transform. Which is why the same file looks different outside of full Rec.709 color on a Mac ... or anywhere else.

That isn't opinion, it's just the practical "what is".

Now, how is Adobe supposed to solve that? I'm quite serious here.

What do you want Adobe's video people to do about this, being as they have no control of what Apple chooses to do whatever.

So again ... how is Adobe supposed to fix a choice by Apple?

Neil

[R Neil Haugen]

To "default"s second post ... that same video will have full saturation and shadow depth if viewed on a full-on Rec.709 setup.

It is only when viewed with an incorrect display gamma on a Mac that it will seem to be lighter in shadows and low-saturated. As if you send that file to me or anyone with a full Rec.709 viewing system, it will look as it does within Premiere on your Mac.

Neil

[Alan 5555]

Well @R Neil Haugen ,  I have found that is not actually the case.  The same happens with Windows as well.  Furthermore that file that you are saying will look way darker outside the mac sphere does not look darker outside the mac spere.  if I export a file without the compensation LUT and upload to say, Frame.io and then move outside the mac sphere and check how that file looks by checking on an Android tablet or phone / or iPhone it stillo looks brighter than it should on all devices which I'm afraid leaves your theory incorrect.  I wish it didn't.

[R Neil Haugen]

I work for/with/teach pro colorists. I've been doing so for years now. So both at NAB and online, I'm part of discussions with many of the top colorists and also the color management/calibration experts like the main person at LightIllusions/ColourSpace.

NOTHING I've posted here ... well, very little ... is personal information. It comes from the top industry experts in both theory and practice. And believe, pro colorists tend to have both theory and practical interests.

It sounds like you are insisting that the same file will look the same when viewed on a display with two widely varying tranform/gamma functions. 

Over the years, I've tested a ton of files sent by Mac users with or without the Adobe "gamma compensation LUT" ... and that is both in Premiere and Resolve studio, which I use daily.

On a highly calibrated and profiled monitor. I didn't just run a calibration, but also ran a profile pass, with ColourSpace using Resolve as the TPG, and providing me with charts of the after-calibration results. I do not work with it unless the profile shows calibration with that all-important low delta-E numbers.

My setup is based on broadcast specs ... sRGB primaries, Rec.709 profile, gamma 2.4, brightness 100 nits in a pretty darkened room with a measured bias light level on the wall behind the 'reference' screen. That's my viewing situation.

Using appropriate CM settings in both Premiere and Resolve, I get identical view and scopes displayed in both apps.

I've never had a submitted file from a Mac user with the added LUT that displayed 'correctly' on my screen and scopes. Ever.

Conversely, the files that were instead simply exported from Premiere without the LUT nearly always are pretty decent. They weren't produced on a full b-cast setup, but for most general use, they'll probably work fine.

And the discussions of NCLC tagging, and/or what "should!" be the standard, all of that, are long, detailed, and at time mind numbing. But at the end of if, if any Mac user sets their monitor to the new option of "HDTV Video (Rec.709-Bt.1886)" ... the issue seems to go away.

Magical, that? Use the same standard, why suddenly ... there isn't a problem!

[Größen33335763suua]

Well that Dilemma can be solved by using Davinci Resolve^^ because Davinci Resolve does it correct.

So i ask again the Question: Why does Adobe dont change their program?

Its a Worldwide Problem with this, users even make LUT Files to correct this, and that even dont work for windows. For that Price u have to pay for Adobe Premiere Pro u get something like this? Its ridicolous.

[R Neil Haugen]

I don't know what part of reality some people have trouble understanding. And note, I work for/with/teach pro colorists, mostly based in Resolve. I use Resolve quite a lot, and ... as I work for/with and teach pro colorists ... I have been around "this discussion" with top tier colorists and the folks that make the calibration software used by the colorists for their spendy monitors.

Over the last five or so years. Hours of presentations and discussions, both at NAB and online. Hours of reading white papers and tests ad infinitum.

 I know the issue. And the frustration that Resolve based pro colorists have with Apple ... and they're mostly Mac geeks. So ... again, here's the history of this issue.

When Apple came out with the Retina monitors and then ColorSync, for some unknown reason they built in the assumption that the OETF function of the camera ... essentially gamma 1.96 ... was the appropriate display gamma. (Boy, does that lead to some down-the-rabbit hole discussions ... )

After Apple came out with their odd 1.96 display gamma, the Resolve devs added an option called Rec.709-A, and yes, specifically, A is for Apple. Why? Very simple.

Because the entire 'broadcast world' used a screen (display) gamma of 2.4 with Rec.709/SDR media. And yes, that specifically included Resolve.

The "Rec.709-A" option was their attempt to make 'basic' Mac users happy. Even if the result wouldn't fly in professional broadcast usage. Btw, Mac has a ton of user options that users shouldn't use, normally ... because they'll mess up your media. But they seem to feel hey, you wanna mess yourself up, have at it ... 😉

(And this is a constant humor dicsussion among colorists, tales of users setting screwy things then wondering why it's ... darn ugly ... )

So did Adobe create the problem? No.  And prior to Apple's odd display gamma, Resolve didn't have the Rec.709-A option either.

So Resolve tried to give users an option to make them happy ... even if it was not "correct" ... which was the option for Rec.709-A for Apple. The problem being, a show you worked on set to Rec.709-A might well not pass the QC machines, but hey ... again, that's your problem, not theirs.

Adobe took a different direction. They kept the broadcast standard within their system, but decided on using that "gamma compensation LUT" at export as a way to allow Mac users to set their media to Apple's unique view if they chose. Essentially a different route to allow users to get to a similar result.

Neither approach was "right", both allowed users to create a file that might well not pass QC machines, but hey ... again, that's your choice.

Now, with the 24.x release, the Premiere devs have included a user settable viewer gamma for the Program monitor. You can choose 2.4 (broadcast), 2.2 (web), and 1.96 (QuickTime), the latter being the one to match your Mac's odd Rec.709 setup.

So ... Adobe is giving you now what you supposedly want ... use it!

Although ... be aware! ... Apple has recently introduced another issue ... being Apple, of course. It's actually a 'fix' for their own mistake, but it's an additional option apparently on most newer Macs.

It's to set the screen display to "HDTV" ... and if you do, you get full-on Rec.709 with display gamma of 2.4.

So ... use the 1.96 viewing gamma all you want! Just understand, on most PC/Android and pro systems, you media will not look what you would consider "correct". But past that, it won't even look "correct" on all Macs, because some Mac users are now setting theirs to "HDTV". Which gives a correct display gamma for Rec.709 'standard' setups.

Ain't life a joy?

[happybelated]

I'm on Mac, and Adobe's LUT does not produce the same grade as their program's display window. It's darker, but not even comparable when it comes to the color and look of the media. Adobe has still yet to offer a half-decent solution to this problem, obvioulsy keeping in mind that the world isn't just going to move to PC.

[R Neil Haugen · Accepted solution]

Why are you still trying to use that LUT? Have you tried the QuickTime/gamma 1.96 option in Premiere's color management?

Oh, and have you properly setup all the color management settings now in the 24.x series?

As nearly everyone who's posted here having troubles has unfortunately not set their color managment up consistently. Well, very understandable, as so many things are new.

Although I do wonder why so many Apple users expect Adobe to somehow magically fix what Apple chose to break ... and quite uniquely so. As it isn't just "PCs" ... it's all of broadcast standard systems that Apple chose to ignore.

The issue is two parts, a display transform and a color space transform. Apple chose to apply the listed camera transform for Rec.709 as the display transform, of gamma 1.96. Which "the standard" says is supposed to be a mathematical tranform using the bottom of a gamma 2.4 curve, which is what everything else uses for Rec.709 display.

And I found out recently, from the testing of a noted color scientist type, that clearly the conversion applied to Rec.709/sRGB files by ColorSync on the Macs doesn't properly remap the sRGB colors within the P3 of the monitor space either. So that is where the slightly desaturated view comes in.

You can't display a file with two separate gammas, and a poorly done color space transform, so it looks similar on systems using those two differing displays. And that means that you cannot produce a file to look 'exactly' the same on a Mac Retina (without Reference mode) monitor and any broadcast spec display.

In fact, a Mac with Reference modes, using the HDTV setting, will see the same gamma 2.4 display for Rec.709 video as any other b-cast spec system ... including TVs.

So it's really a pick your poison for users. If you need to pass broadcast QC, you gotta use a display to correct on, that is correctly set for Rec.709 with gamma 2.4.

If you worry only about Mac users without reference modes, in web viewing, then probably the QuickTime gamma 1.96 setting is what you want. But do so knowing that all Macs with reference modes, and all non-Mac screens, will see a very different image. Probably too dark, crushed blacks and maybe clipped whites, and over-saturated.

Or do what most colorists do, and as expected, the majority of them are total Mac geeks ... and ticked as Hades at Apple. No professional media is produced at the gamma 1.96 setting ... period. All professional Rec.709 media is produced with a monitor setup to sRGB,. D65, 100 nits brightness, gamma 2.4.  (Occasionally gamma 2.2.).

[Adnan A. Nazzal]

In my simple humble knowlege, I been suffering for more than 15 months about colors are not maching the premiere pro after export till i figure out follow thing:

1- If you export for web usage: Youtube , FB, Instagram and others , displayed on PC Monitor or iPhone or iPad ,,, the best way is to set up the project settings as color on Viewer Gamma 2.2 (WEB) , exporting HEVC  with match sequnce settings, render at maximum depth check , Used maximum render quality check , High Tier, CBR 80 ( 4K ) , in this way, all OK , the Video is everywhere as it was edited in Premiere pro 

2- If you looking to play the youtube OR the exported video on a TV Screen, just add the Gamma compensation Lut on filters at export, then your video will be matched everywhere as been edited in Premiere Pro 

[R Neil Haugen]

 Make a new sequence, say 1920x1080. Put a Bars & Tone on it, to get that pluge. Stretch it out to maybe 30 seconds. 

Now export with that 'gamma compensation LUT' on it, as you suggest. View it on the TV.

See what the pluge looks like, especially the dark sections that are supposed to show the shadow limits. Post back your results.

[Adnan A. Nazzal]

Dear Neil,

I did exactly what you said, the rsult is:

i have color banding 

the dark grey color in the down area is not that visibil 

conclusion: am totally confused 

i just uploaded a podcast worked as web 2.2 and exported asi mentioned previosly , looks like washed up no colors and flat 

am really confused .

my monitor was Rec 709 and 2.4 Gamma, now am swetching back to SRGB and working on 2.4 , knowing for sure is what am seeing on my premiere pro display is not what am going to have after i export from premiere pro in HEVC with gamma compensation filter applied.

am working on PC, if you suggest me a workflow, you simply saved me a 1 year course that am going to do on Davnici Resolve ,, am really tired of this  

[R Neil Haugen]

Hey, color can be so freaking confusing and frustrating! Every so often I need to re-do my calibration, and I always put it off too far because i hate the entire calibration process. It's mind-numbingly boring, and it's so darn easy to miss something ... and have to redo the entire half hour process you just 'completed'.

And then running that profile pass, Colourspace using Resolve as the TPG ... to check the calibration. And the resultant chart is ... just ... not quite ... close enough. I've got to tweak something, and do the whole flipping thing again. 

Typically takes at least a half day for me. I've had colorists tell me if I did this righteously every 3-4 weeks, I'd get it down to an hour and a half, two hours. Haven't done that yet.

Banding can come from two things ... as especially with an H.264/HEVC export, the block method that is used for compression will cause both blocky artifacts and banding if the data rate drops below what is needed for any part of an export.

What I mean by "block" is the encoding process looks at say 4, 6, 8, 9, or 12 pixel "blocks", and if they're all within a point or two between R, G, and B values, they save data rate by turning the entire block to X/Y/Z rather than their original pixel values. So a smooth gradient is now a series of 'small' ... but noticeable ... jumps.

So how do you know what bitrate and encoding process (Main, High, what profile 4.1, 5, whatever ... ) is needed?

Test. Export, and if you get banding/blocking artifacting, up the bitrate or process encoding level.

The other way to get banding is normally with 8 bit media ... with only the 255 value levels black to white ... stretching any part of that clip much for color correction, or for color space changes, can cause visible 'breaks' where there isn't a couple neighboring 'levels' anymore.

That is why it is incredibly important that all 8 bit media be exposed as close to "perfect" for that job as possible, and to have been properly white-balanced in camera to also be close to final white balance. As any needed visual changes to exposure, contrast curve, and white balance can result in banding at times.

I will add that some cameras that say they produce "10 bit" ... produce extremely thin 10 bit. You do hardly any pushing of that in color, you get blocking/banding/aritfacting. Which you shouldn't with really correct, full 10 bit media.

[Adnan A. Nazzal]

let's put a side the color banding...

about the project color settings, do you recommend follow:

color space broadcast 2.4 and export with Gamma compnesation effect ?

[Adnan A. Nazzal]

i like the video how its displayed in 2.4 project , once i export it without gamma filter, its looks like washed out without colors, once i export it gamma compensation filter, its looks like darks.. am totally cofused 

[R Neil Haugen]

Are you on a Mac? If so, does it have "Reference modes"?

And if on a Mac, what does that look like in say VLC as compared to QuickTime Player?

[Adnan A. Nazzal]

I work on PC ,, i use to have rec709 color on monitor ,, am switching back right now to srgb 

if you want,, i can sent you 2 links for the same video : one worked into a project of web 2.2 and the other one on project broadcast 2.4 used gamma compensation effect on export :

this is web : https://www.youtube.com/watch?v=m56UY6Ngc_M

this is sample of broadcast 2.4 with gama compensation effect on export: https://www.youtube.com/watch?v=Gjh83BHKMVg