"Display Color Management" not working properly?

I'm on my tablet, not my desktop at the moment. So I don't have the bunch of links available. I've got a long, long list of them. The Rec.709 standards have been the basis for all pro broadcast/long-form work for quite a few years now.

I'm a contributing author over at MixingLight.com, a pro colorist's subscription site. CM issues are the daily talk of colorists, and covered in many of the tutorials there and elsewhere.

Also there are many articles by people like Steve Shaw of LightIllusions, the company that makes Colourspace, one of the top two color management calibration/profiling apps used by the industry. Including direct comments on Mac and the odd application of Rec.709 CM.

Much of the YouTube materials I've seen on CM and especially Premiere and Mac's CM are worth exactly what you paid for them. If you don't pay for YouTube that is.

I did an article and tutorial a couple years ago on Premiere's CM for MixingLight. It is still available there, and I believe still outside the paywall, available for anyone to see. I spent hours on phone calls and Zoom with Francis Crossman to prepare for it. He was then "merely" a color engineer, now is co-product manager for Premiere Pro. I gave a presentation on it in the Flanders Scientific/MixingLight booth at NAB 2019.

And then before publication, there were numerous emails between Lars Borg, Adobe's chief color scientist, myself, and Robbie Carman and Pat Inhofer, two of the founders and both noted colorists themselves. They had tons of highly technical questions they wanted answered specifically to double check everything in my article/tutorial.

So ... I've been through the details thoroughly, and my comments are not just off the cuff. And at the moment, I'm working on testing a TON of different media and workflows as with all the changes in CM in Pr2022, it's time for another detailed article/tutorial.

Also note, most colorists are Mac people so my understanding of Pr/Mac interactions has to be accurate. I'm also always open to corrections ... as not only the Premiere CM is changing, it seems nearly everything is in transition.

If you get deep into color science for video imagery ... you get heavy into camera/scene referred transforms, timeline/working spaces, display transforms, IDT, EOTF, RRT, and more acronyms than you can track. A massive and deep rabbit hole that can mimic a black hole it is believed ...

I didn't say anything about two different 'curves' but that the official Rec.709 standards allow for a primary gamma of 2.4 in a room with a specified maximum light level ... it's fairly 'dim' ... and precise standards for the backlight upon the wall behind the Grade 1 reference monitor also. The monitor to be at 100 nits.

However for working in a "bright room environment" the standard doth allow also 2.2. Which is often used also when doing work intended for the web. So there's a preferred gamma, and an allowable one given a brighter room. Which affects how we react to brightness ... hence it makes perfect sense.

Premiere's origins are a totally Rec.709 closed system. It assumed it didn't need to do CM because the user would know to be on a totally calibrated/profiled Rec.709 compliant system.

Then Mac came out with the Retina monitors, a beautiful screen ... but with ColorSync using 1.96 gamma and not applying the required second transform (also known as Bt1886). And trouble ensued.

Premiere's developers came up with first the Display color management option, which tells Premiere not to assume Rec.709 monitor, and instead check the ICC profile of the monitor and remap the image to Rec.709 within that ICC profile. Then additionally, a LUT that could be applied in the export dialog to 'mod' the file darker so it looked the same outside Pr on a Mac as it did inside.

Unfortunately that also means it looks darker on any fully Rec.709 compliant system. And will typically fail any broadcast quality control check.

BlackMagic's engineers tumbled to the odd datum that ColorSync will apply gamma 2.4 if you feed it the second NLC tag of "2" ... which is by the standards listed as "unspecified". So they decided to offer the export option of "Rec.709-A" and yes, A is speficially for Apple.

That embeds the NLC tag 1-2-1, and ColorSync will use a 2.4 gamma. Yea!

Unfortunately, that means that on many non-Mac systems, you still end up with a file that plays much darker. Not ... so good.

Because you cannot make a file that will play the same when treated with strikingly different CM practices. But as we move more and more into HDR, over time this may become moot.

Neil