export settings Mac user

[Jesse Vulink]

Hi All,

I have recently build a grading suite. a neutral grey back wall, all lighting is 6500 K. My hero monitor is the Eizo CG248 and my client monitor the LG C1. 

I have my monitors set to rec 709 gamma 2.4 and work mostly color managed. See my settings below.

When i export my project in gamma 2.4 and upload it to vimeo my grading has less contrast as in my viewer in Davinci.

So I chance the output color space to rec709-A, it looks better this way on vimeo but it makes my picture darker and heavier in contrast.

I am wondering if someone can help me with this: what is the right workflow when working on a mac mini.

Does it mean I have to export my project in both gamma 2.4 (screens, broadcast) and rec709-a for web?

Cheers, Jesse

 

[Matthew Blacklock]

Hey Jesse,

Are you running your displays through a card such as a Blackmagic Ultrastudio? Or are they direct HDMI out of your Mac mini?

This all comes down to gamma tagging and macOS colour management. Basically you'll want to enable "Use Mac Display Profiles" and set your output colour space to Rec.709-A on your project and outputs and grade with those settings for it to look correct on any UI displays and outputs destined for Quicktime, Vimeo, Frame.io, etc. 

Let me know if you're running direct to displays or through a capture device and I can give you more specifics on what has worked for me in my set up, as I've recently been through this in setting up a suite. 

thanks!

Matthew

Edited April 26, 2023 by Matthew Blacklock
Updated/added more detail

[Jesse Vulink]

Hi Matthew, thanks for the response. I have my hero monitor set to clean feed, using a hdmi cable directly in my Mac mini. For my LG oled I have the blackmagic design ultrastudio 4k mini.

I have attached my settings.

[Matthew Blacklock]

Cool, really helpful to know some more of the details of your set up. 

This is what I would do based on my experience and understanding of how macOS handles colour management and how that interacts with Resolve. Worth noting I'm typing this from home so I don't have my machine connected to be able to check the exact settings at the moment, but will try to confirm next week. 

First off your client monitor. I believe Resolve will default to sending a Rec.709/Gamma 2.4 signal through the Ultrastudio to the displays connected and it bypasses any system-level colour management. And if you change the project Output colour space, it won't affect the image that is sent through Ultrastudio. To test this, load up an image in a project and then change the output colour space in your project settings to a few different arbitrary settings, making sure you save each time to have the project update. In my experience this setting doesn't alter the image on the display connected to the Ultrastudio, so assuming your client TV is calibrated, it will display an accurate image regardless of the project settings. 

Next the Eizo directly connected to your machine. Anything running direct out of the Mac via HDMI/USB-C/Thunderbolt is going to be subject to the macOS colour management pipeline, even when used as video clean feed in Resolve. This means that the ICC display profile (or reference mode if you're ever using a Mac with an Apple XDR or Studio display) selected in System Preferences will impact what you see on your display connected directly over HDMI. It's been a little while since I last tested it, but I'm pretty sure even with the "Use Mac profiles..." disabled in Resolve the profile selected in System Preferences will still impact the image that is displayed. Worth having a play flipping through different profiles to see if this is the case on your setup. 

To get it set for colour critical viewing, I'd install the ICC's Rec709 Reference display profile onto your machine and select it as the profile in system preferences for the Eizo when connected: https://www.color.org/rec709.xalter

Then I'd enable "Use Mac display color profiles for viewers" in Resolve and set your project output colour space to Rec.709-A. It's a hack, but the Mac should effectively pipe the transforms through its native DisplayP3 space and then out to the Eizo as Rec.709/Gamma 2.4. Again, assuming it has been calibrated to the spec, it should then display an identical image to what's on your LG going through the Ultrastudio. 

It's worth going through and testing the effects that changing the colour spaces in Resolve or profiles in System Preferences has on the image displayed on each of your monitors. If my understanding is correct, the above recipe should get everything to quite an accurate place. Then when you export with the Rec.709-A tag, again everything will be displayed consistently when delivered to the web, etc.

I've received mastered files from some of the major post houses with "1-1-1" colour space metadata tags, which is essentially what exporting with the Rec.709-A tag assigns to the file. It doesn't change anything about the file itself, it just instructs Quicktime, Frame.io, Vimeo, YouTube, etc how the image should be displayed. If you are delivering to broadcast, then instruct them it's been graded to Rec.709/Gamma 2.4 and they should be able to interpret it accordingly. 

 

Here's a few more links that might be helpful: 

A thread where I discussed my facility's setup using Apple's Pro Display XDR and an LG in our suite: 

 

Here's a detailed article on ICC profiles and their pitfalls which has informed my understanding: https://www.lightillusion.com/what_is_wrong_with_iccs.html

And a video from Filmlight going into the depths of different display colour spaces: 

 

[Jesse Vulink]

Thanks so much for the response! Very useful information! 

The only question that still remains is: do I need to export rec709 gamma 2.4 for screens/oled and broadcasting and rec709-A for web?

That means that I will color grade in gamma 2.4 (since my hero monitor is set to this and my project aswell). And export in both gamma for different viewing.

[Matthew Blacklock]

Sorry for the delayed response, been a full week.

Personally I would stick with exporting everything as Rec 709-A. As far as I understand it is only metadata so won't change anything about the file itself, it's only telling Quicktime/Vimeo/YouTube/Frame.io how to display the file's contents.

Tell any broadcasters you are delivering to that it's been graded for Rec709 Gamma 2.4 and they should be able to fit it into the pipeline accordingly, regardless of metadata tags. 

And actually, when you open up files tagged Rec 709-A, Quicktime says they are technically tagged correctly (1-1-1 / ITU-R BT.709) as opposed to "Unspecified" which you get when exporting with the tag set to Gamma 2.4.  Most, if not all, mastered files I've ever received from other large-scale post houses are also tagged with the Rec 709-A/1-1-1 tagging scheme, so if they consider that to be the best then it's good enough for me for final deliveries. 

Hope that helps and if anyone out there has a better understanding/experience please feel free chime in.