Colored rec.709 ProRes Log files result in desaturated ProRes exported visuals

[ip Edit]

Oh great and powerful Premiere Community.  Referencing this post from 2022, to try and get more clarification.  Assuming the scenario Mighty Neil describes is still an issue for Macs, generally, then what is the best work around? 

Simple (and common) scenario:  Editing and coloring on a timeline with ProRes444 clips, shot in Log, with all clips being manually overriden to the Rec.709 color space (even though the clips are already Rec.709 by default), and the project settings are set to Rec.709 too.  Exports, however, appear overexposed, desaturated, and generally "washed out" in comparison with the perfectly colored piece that appears in my timeline.  Yes, viewing the exports on a Mac, both via File Preview, as well as via Quicktime.  Bring the export into Premiere and it looks fairly close-matched to the look of the timeline edit (Source Monitor/Program Monitor side x side).

Since 2022, I can see at least one change to the Project Settings tabs; the ability to change the "Viewer Gamma" to 2.4 (Broadcast), rather than 1.96 (Quicktime). 

I have a few questions. 

First, it's 2025, not 2022; so, what gives (why still)?

Second, should my various tech teams (the ones broadcasting the exports onto screen in a live venue) expect to see a different result, dependent upon the hardware projecting the video file (i.e. Mac vs. PC; or AJA vs. Blackmagic.

Three, how do I explain the issue to a non-tech-savvy Producer in a way that dissuades blame from being projected upon my Editors?

Four, is the QT Gamma Compensation LUT still considered a viable band-aid for this scenario?  (I used to only need it when exporting H.264 video files.  Now it seems I need to use it on ProRes QTs too?)

Finally, it's 2025, not 2022.  What gives?

Hear my cry O' Land of Neil the Legendary.

[ip Edit]

Sorry, didn't reference the 2022 post:

https://community.adobe.com/t5/premiere-pro-discussions/export-color-and-brightness-issues/m-p/13091...

[R Neil Haugen · Accepted solution]

The root cause hasn't changed.

The long-accepted specifications for display of Rec.709 video require the use of a display transform essentially similar to gamma 2.4 ... it's actually a "power law" mathematical formula, but it's close enough to "simple" gamma 2.4 that that is what it's referred to as.

Macs ... but ONLY on Macs without Reference modes! ... apply essentially a gamma 1.96 display transform IF you use an app that allows the Mac ColorSync utility to set color management. Such as QuickTime player, Chrome and Safari browsers.

The image is much lighter, more notable in the shadows/mids, and appears desaturated. A colorist I've read did some extensive testing, and says it isn't just desaturated due to being lighter, there is a mis-match in the transform of the image sRGB spectrum into the native P3 color space of the Retina monitors. So Apple got both the luminance transform and the color transform wrong.

However ... Macs with Reference modes set to HDTV, and on 'normal' Macs when using VLC or Potplayer, or Firefox browser ... will normally use a correct Rec.709 display transform and therefore the image will be much closer to the proper display of those pixels.

The choice is essentially still the same ... a correct Rec.709 image, OR ... one that looks "fine" on the improper Mac display transform but too dark everywhere else.

As to how you work, if you want the Mac 1.96 look, set the Display Color Management on, Extended Dynamic Range (for Mac users) ... and the auto detect log, auto tonemapping, viewer gamma to 1.96, and sequence CM to Rec.709.

Your image within Premiere will look very similar outside on a Mac without Reference modes while using QuickTime player, Chrome or Safari. You may be happy with that.

However, anyone on a standard broadcast spec system, PC, most TVs, and Android devices, will see a much darker, more saturated image.