The Impossibility of Accurate Color for Video

We all want accurate color in our video. But, good golly it’s hard, as this conversation between Gary Bowman and myself illustrates.

Gary begins

I’m hoping you can assist me in finding the other end of a rabbit hole. I while back I purchased your DaVinci Resolve bundle as part of wanting to make the switch from Premiere. (I have taken other courses from you as well.) In general, I think DR kills it, especially the Fairlight page. If you can shed some light or suggest somewhere to look, I would be very appreciative. Here’s the scoop:

I am using a fairly current iMac with second monitor. I have done the best I can with the built in calibration settings. I am unsure of which profile to use, but so far have created a 6500k R709 2.2 profile on the iMac and the LG Ultrafine. It seems a little dark, but from what I read, this is a good starting point.

My goal is solely creating educational video for the web (Vimeo hosted). There will be no feature film or TV. I’m shooting 4K, 10 bit, S-Cinetone profile, with a couple of Sony A7 IVs. (S-log just isn’t convenient for run and gun in a classroom.)

The issue I need to nail down, is consistent output whether viewed on a Mac, PC or online. Typically, the online stuff looks a bit brighter / better balanced. Initially, I had problems with the output looking washed out until I got onto using rec 709a. Still, the online and desktop files look different and it is tricky to know how to proceed.

Initially I fumbled around using CST nodes, but my understanding is this is not needed. I have also tried setting up a color managed enviro using WG/intermediate. Aside from understanding what the system is doing and getting consistency, is the fact that what I see online looks different and better than at the editor. Whew, that was a lot. Thank for your time. If you can offer assistance or direction, that would be fantastic.

Larry replies

Well, there’s the technical answer and the real-world answer. No, actually, there’s only the real-world answer: “It just doesn’t matter.”

Let me explain. You are correct, you need to configure your monitor to match the Rec. 709 spec, with a gamma setting of 2.2 (to match broadcast specs) or maybe 2.4 (to match Apple specs) or possibly 2.1 to match earlier versions of Windows, I think.

Can you see the problem?

Next, you need to determine whether the audience/client/viewer is watching on an analog or digital monitor or perhaps a projector. Oh, you need to know which operating system they are running, whether the monitor is LED, LCD, OLED or micro-LED, what color space the monitor is configured for – P3, SRGB, Rec. 709, Rec. 2020, or “Well, golly, that looks pretty good to me!” You should also know how old the monitor is, and how far they’ve cranked the brightness.

Can you see the problem, yet?

You need to know what proprietary codecs and conversion software each social media server uses, whether they opted for small file size or color accuracy. Whether they compressed it into an 8- or 10-bit color space, used 4:1:1, 4:2:0, or 4:2:2 chroma subsampling.

Hmmm… Can you see the problem yet?

Your question is exactly the same one I was asking 40 years ago in broadcast television: “Why doesn’t the TV program look as good at home as it does here in the control room?” And the answer is the same: “Because you don’t have any control over the distribution pipeline, nor do you have control over how the viewer has configured their TV set.”

ALL you can do, as the telephone company used to say, is to make it look as good as you can leaving your computer and heading out into a very diverse world. You have no control over distribution, downstream compression, or how the viewer configures their monitor.

You have no control. Period. All you have is the ability to make it look as good as you can, then relax and let it go.

– – –

Now, if you are in a fully-controlled environment, where you are sending images created by color-calibrated software, viewed on a color-calibrated monitor, to a color-calibrated printer using color-calibrated inks, where every step of the process is linked in a standardized color management system, like ACES or ICC, and each step is precisely controlled, you can nail your colors down tight.

This is how the printing industry works. It is also how digital cinema works. Every device is calibrated, characterized, standardized, and nothing leaves the chain. But that’s not how most video is distributed.

Video on social media makes creating sausage look refined and elegant. As soon as you upload your video, you’ve lost control, because it is outside the color management chain.

Do your best to make your software and monitors as reasonably accurate as you can. Make your images look as good as you can. After that, like a proud parent watching their young children stride out into the world – you just hope everything turns out alright.

It’s all we can do.