citizenmike wrote:Uh oh, now I'm confused again. I'm not really worried about how things look inside QT Player right now — just trying to get a bead on what I'm seeing in Resolve.
You said "Yes, it should be Rec.709 equivalent preview on P3 screen (so not badly oversaturated one)."
I took that to mean that: despite the fact that my iMac has a P3 color profile, if I enable the "Use Mac Display Color Profiles for Viewers" option while in a Rec 709 2.4 Resolve project, that Resolve will show me images within its viewers as if I'm looking at a Rec 709 2.4 monitor.
Am I right or wrong?
Thank you.
Unfortunately in Resolve 15.2.3+ it won't as for 2.4 gamma based projects BM does special correction which is designed to give same preview as QT X, not
correct one.
If you go back to 15.2.2 then in theory it should give you correct preview (regardless how accurate screen is). It should match BM card preview on the same monitor. What we want to achieve is same preview over GPU and BM card on the same monitor (with same settings). Once this is achieved you just need to calibrate monitor and then it will be accurate.
Imagine we have P3 screen with 2.4 gamma and its profile describes it 100% accurately. Profile info is used by OSX color engine for any processing, so it has to be accurate. Lets just assume everything is 100% perfect. In such a case Resolve viewer should be fairly accurately able to show you any smaller gamut based format, eg Rec.709 with 2.2 gamma. At this point we have 100% accurate P3 preview, so rest is just "pure math". Of course it can't be wider gamut as then screen can't display it by its "physical" limitation. Anything below its physical limitations can be achieved by pure math (either on GPU, as LUT or on external box, etc). This is exactly what good monitors do when you switch between their presets P3 vs REc.709 or different gammas. In order to make it even more accurate we calibrate screen on regular basis, so then you are certain that your preview is accurate (fact that it left factory even well calibrated doesn't really guarantee it's accurate months later).
When you read Resolve manual remember it's all related to Resolve, not every tool. There is absolutely nothing to stop you to achieve 100% color accurate preview (actually more accurate than any SDI card there of you want to be pedantic) over GPU monitoring.