Use Mac Display Color Profiles for Viewers

Here is a newbie question.

I'm grading in Resolve Studio 15 on an iMac 5k Retina with its default color profile chosen in System Preferences. Unfortunately, I don't yet own an external reference monitor. I enable the "Use Mac Display Color Profiles for Viewers" option. What am I now seeing in the Resolve viewers?

Is Resolve a) now compensating for the iMac's P3 color profile, so that the Resolve viewers look Rec 709?
Or is Resolve b) now making its own viewers look P3?

Thank you for any help.

Whatever you have set in project setting is converted to screen profile. It's not Resolve but more Apple color engine doing conversion.
In theory this should be fine, so if you have Rec.709 set project then your preview should be correct (not oversaturated), but in practice this is not so ideal as screen is not calibrated and there are "other" issues.
Another issue is that QT X uses wrong gamma for Rec.709 tagged files, so it won't match Resolve <15.2.3 version. 15.2.3 compensates for this, so 2.4 gamma based projects will match QT X, but this doesn't mean preview is correct. It's actually very wrong. All messed up Depending what you grade for: Mac screens/preview or TVs/PCs etc you may be better of using Resolve 15.2.2.

Thanks so much for your reply, Andrew. Good to know about Resolve 15.2.3.

But I'm still not sure I understand 100%.

My Project Settings are set up for Rec 709 2.4. The iMac display is using its default P3 profile. I am enabling "Use Mac Display Color Profiles for Viewers." Does that mean that, within Resolve, the Viewer windows now show Rec 709?

And I can definitely see that when I export something and open it up in Quicktime Player on the same monitor, it's washed out — I can adjust for that in my workflow, but just wanted to make sure I get what "Use Mac Display Color Profiles for Viewers" is actually doing.

Thanks so much for your reply, Andrew. Good to know about Resolve 15.2.3.

But I'm still not sure I understand 100%.

My Project Settings are set up for Rec 709 2.4. The iMac display is using its default P3 profile. I am enabling "Use Mac Display Color Profiles for Viewers." Does that mean that, within Resolve, the Viewer windows now show Rec 709?

And I can definitely see that when I export something and open it up in Quicktime Player on the same monitor, it's washed out — I can adjust for that in my workflow, but just wanted to make sure I get what "Use Mac Display Color Profiles for Viewers" is actually doing.

Yes, it should be Rec.709 equivalent preview on P3 screen (so not badly oversaturated one).
With 15.2.3 and 2.4 gamma setting your exported eg. ProRes should perfectly match between QT X preview and Resolve viewer (only for 2.4 gamma though!). Problem is that it's not correct preview, eg. won't match proper reference screen over BM card. BM in 15.2.3 is compensating for the fact that QT X uses 1.96 gamma for Rec.709 tagged files, so this is quite far from your specified 2.4 (and what Resolve 15.2.2 will show in its viewer).
Maybe 1 day I will compare Resolve GUI viewer with BM preview to the same monitor. It doesn't matter if monitor is accurate or not, but if both previews are the same (with correct project/monitor settings).

Thanks so much, Andrew. I wasn't sure whether "Use Mac Display Color Profile for Viewers" meant that Resolve was "compensating" for the Mac color profile or "implementing" the Mac color profile in the Viewers. Sounds like it's compensating for the Mac color profile in order to show Rec 709.

I appreciate the wisdom!

No, it's including Resolve viewer into OSX color management pipe.

Resolve 15.2.3 does something additional on its side for 2.4 based gamma projects in order to provide same preview result as QT X, but this is a poor hack.

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.

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.

You can explore this thread: viewtopic.php?f=21&t=69373
I think you will not find a simple answer but it's interesting and you can see how difficult it is.

And this is right about the part of the thread where I jump in and remind people to page 1885 of the Resolve 15 manual: "Limitations When Grading With the Viewer on a Computer Display." This goes into some detail why you cannot accurately monitor directly from the computer and operating system. You have to have a color-managed output, like one from a Blackmagic display card, preferably on a calibrated external Rec709 display.

Thanks for all the replies. It sounds like I had exactly the wrong understanding of what "Use Mac Display Color Profiles for Viewers" does.

It does what it says. You are not wrong, but unfortunately BM (after initial fix) changed it in 15.2.3 into some "need to look like QT X" feature, not a proper reference look.

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.

I read through this thread and also the manual. I too, am still a little confused on what "Use Mac Display Color Profiles for Viewers" is, and how it works. I grade exclusively on my Macbook Pro, using it's built-in monitor. Sometimes I grade on an LG monitor connected to my mac via HDMI.

So with my exclusive Mac setup, should I have that option checked or unchecked?

In Davinci YRGB, I changed my timeline color space to "ACEScct." Display looked fine.

I turned on "Use Mac Display Color Profiles for Viewers." Then the viewer gets insanely contrasty. But when I export to H.264, it looks as it did before I turned on "Use Mac Display Color Profiles for Viewers."

It sounds like, with a Mac only setup (although not ideal, I understand) my best bet would be to leave "Use Mac Display Color Profiles for Viewers" unchecked?

Thanks all for your patience!

You can, but depending if you have wide gamut display or not you may end up with saturation issue. You would need to compensate this with preview LUT.

I read through this thread and also the manual. I too, am still a little confused on what "Use Mac Display Color Profiles for Viewers" is, and how it works.

You're not alone. Bear in mind though, that this is an old thread, and Resolve 16.2.3 has changed a lot from Resolve 15. BMD have added Rec.709-A, which addresses the Quicktime gamma shift discussed above. There's a sticky thread about it at the top of the forum.

Personally, I'm of the opinion that until you're using a calibrated reference monitor, you can't expect accuracy. So, to me, the "Use Mac Color Profiles" checkbox is a moot point; it doesn't affect reference monitors. I know that might come across sounding a little elitist, but don't take it that way. I don't have one at the moment, either.

Totally understand! From what I can tell, setting the timeline color space to something with a wider gamut than my macbook display, shows highly contrasty and saturated images. And when still using that setting, and exporting to H.264, the rendered video looks as it did when I had "Use Mac Display Color Profiles for Viewers" unchecked.

Seems to me that maybe those of us using our computer monitors should maybe leave it UNCHECKED for the most accurate representation?

In case it's helpful, after I posted in this thread last year, I also posted in this thread on the Adobe Forum on the subject of color management between Premiere and Resolve.

https://community.adobe.com/t5/premiere ... 869?page=1

Can anybody provide an explanation in Layman's terms for what "Use Mac Display Color Profiles for Viewers" does?

Takes your video preview, looks at project settings and based on this info converts preview to display profile.
If your display profile describes your monitor accurately (it was calibrated) then you have correct preview (assuming your monitor covers gamut specified in project settings).

So this feature was built to help those grading on laptop screens only, monitor more accurately? Or simply to try to resolve the gamma shift from color managed and non-color managed 3rd party viewing apps?

It tries to give you correct preview.
Without color management wide gamut displays (which don't allow to switch to Rec.709 gamut) will be more difficult to use for Rec.709 projects.

Thanks all! After some reading, it sounds like I need to create a display LUT to monitor more accurately with my GUI monitor.

To get as accurate as I can with a GUI display:

I have a SPYDER colorimeter, and will use displayCAL to create the LUT.

Once it's created, I should disable "Use Mac Display Color Profiles for Viewers" and use the LUT for output monitoring? Right?

Or should I have "Use Mac Display Color Profiles for Viewers" ENABLED in combination with the display LUT?