Inconsistent color between Program window and rendered files

[t.linn]

I'm having an issue where I get color looking exactly like I want it (using the scopes and confirming visually) on my calibrated monitor, but when I export the video it does not look the same. I can't figure out why. People who look normal in the Program window look like colorless corpses when the video is played in a browser or media playback software on the same monitor.

I have turned off color management in Premiere Pro so I don't think the problem is a color space mismatch. I'm not dealing with HDR footage. It's all decade-old XDCAM EX footage in Rec 709. I'm exporting to H.265 with the color space set to Rec. 709. This seems pretty straightforward. I can't figure out what I'm missing.

Thanks in advance for any help.

[t.linn]

The upper part of the screen capture is the program window. The lower part of the image is the exported file open in a media player. Media Info for the exported file is below.

[t.linn]

Well, one more detail. I tried playback with both QuickTime and IINA media players. The color was wrong on both. I uploaded the file to my CDN and played it back in Firefox and Edge. Also wrong. But it looks perfect when played back in VLC. What am I missing?

[R Neil Haugen]

The key bit of data you didn't mention was your OS ... and I'm guessing, it's a Mac?

As Apple for some odd reason chose to apply an incorrect display transform for Rec.709  video files. It uses gamma 1.96 rather than the published standard of 2.4, which is why the image is lighter/less contrasty. And from testing a colorist acquaintance published of test media, they don't exactly land converting Rec.709 color onto the monitor's native P3 color space either.

VLC ignores Apple's ColorSync and applies correct Rec.709 standards. Which is why the difference.

Bring the file back into Premiere, it will look as it did prior to export.

Wanna hear another fun one? Some Macs now have "reference modes" for the monitors. Someone with reference modes setting them to HDTV gets ... correct Rec.709 for both tonal (display gamma 2.4) and color (proper color space conversion).

As I run a fully calibrated and profiled system for my reference monitor, what I'll see is what you saw in Premiere.

And yea, it's a right mess, thanks Apple. I work for/with/teach pro colorists, most of whom are total Mac geeks. And they are furious with Apple over this mess.

Oh, you can set Premiere's Viewer Gamma to 1.96 Quiktime, and then you'll see inside and outside of Premiere the same image. However, you do tonal/color corrections for that image, those of use with regular Rec.709 systems will see a dark image with crushed blacks and a bit oversaturated to boot. Yea, funsies.

[t.linn]

Thank you for explaining this, Neil! Yes, I use a Mac—and...wow. If I'm understanding you correctly, the problem is with the file itself and not the way the file is displayed on playback. Is there any workaround besides rendering on a Windows machine?

One thing you wrote isn't consistent with my experience. My external monitors, a SDR BenQ primary monitor and an older SDR Dell, are both calibrated and profiled. Yet I still have the issue. (My M1 Max MBP's display is not profiled.)

[R Neil Haugen]

It isn't a problem with the file per se. And your monitor calibration can only affect the signal it receives, and that's also not the problem here.

The problem is caused by Apple's ColorSync utility, which controls color management for those apps that let it. Like QuickTime Player, Chrome & Safari browsers. As ColorSync uses a display transform of essentially gamma 1.96 on the signal it sends to the monitor.

Rather than the 'normal' Rec.709 display transform of gamma 2.4. Which is used by all non-Apple systems, including broadcast/streaming.

So any app that allows ColorySync to color manage video playback will use that incorrect display transform of gamma 1.96 on the signal it sends to the monitor.

Hence the difference between QuickTime Player/Chrom/Safari and VLC. As VLC doesn't allow ColorSync to color manage the image.

PCs, TVs, and Android devices are designed to use a display gamma of 2.4 for Rec.709 video. As are the Macs with Reference modes set to "HDTV".

How this affects the file itself ... is less understood. You see, Premiere doesn't change the file by applying a gamma to the exported result. That's not how it works.

It's when you are viewing the image within Premiere, and you make changes to the file with that image as showing in the Program monitor ... you have made the changes to the file. It's not an added thing by Premiere ... it's what you've done according to how you viewed the file in Premiere.

Which is why Premiere's viewer gamma (applied to the display signal) should be set to 2.4 for semi-dark room grading ... meaning a pretty dark, neutral (but not blacked-out) room, or gamma 2.2 for "bright room" ... meaning normal room lights on while grading.

Grading in the totally neutral color, darker room, allows for more accurate human visual perception of both hue values and color contrast ... that's why that is the required standard for professional grading.

Broadcast/commercial video is all built on the expectation the material was graded while being viewed in a 'correct' environment. Neutral gray surfaces in any area seen by the colorist, semi-darkened room, a bias light projected at the wall or curtains behind the Reference monitor such that there is a slight (and I do mean slight!) "glow" around the monitor bezel.

The monitor both calibrated and then profiled to check the calibration. 

What is done to the file by the colorist, the choices of tonal and color settings, is done under those conditions, in order to get a consistent end result across colorists and suites.

So Premiere tries to create the proper environment for you to correct the image. The signal out to the monitor is created after the correction you've done to the image inside Premiere. You can now choose which display transform setting you want to use:

1. if you  want the "Mac" QuickTime view 1.96 image to grade, or
2. thankfully, when you are grading in a normal bright office and can (and should) use gamma 2.2 in the Viewer settings in Premiere, or
3. you are in that neutral, darkened room, and can and should use the gamma 2.4 viewer display setting.

Premiere doesn't apply the gamma to the file ... but to the image sent to the system/monitor after all processing of your grading choices.

And this is why colorists must use a breakout device, such as the cards by BlackMagic and AJA, to send the signal to the reference monitor. They want a "clean feed", meaning neither the OS nor the GPU even "touch" the signal, so they can't change it. NO properly setup, professional reference monitor is ever fed directly from the GPU.

The challenge for 'general' editors and amateurs is to get as close to a grading suite setup as you can afford to do. And to understand the capabilities and limitations of your system, so you can take them into account and work through and over them.

[t.linn]

Thank you for this great reply, Neil. It is pretty clear that I am playing checkers while you are playing chess. I am learning some new things here. 🙂 Without imposing on any more of your time to explain why, can I just ask if I am correct to understand that the problem here is the playback of any Rec.709 material on Macs through any software that relies on ColorSync? So the exported file coming out of Adobe Media Encoder on my Mac isn't flawed vs the same sequence rendered using AME on Windows. Re-rendering on a Windows workstation isn't going to help. The problem results from the way ColorSync transforms Rec.709 files for playback on Macs.

If my understanding is correct, this seems like good news for me. There is nothing wrong with my rendered files. And there is nothing more I can do to make my Rec.709 files (which are intended for an online course) more broadly compatible with our students' various computers and mobile devices.

[R Neil Haugen]

That is correct ... it isn't the file, it's the display transform (gamma) that's used which causes the different view of the file.

That's why it's not "right" in QuickTime Player, but is in VLC.

And also correct, for general online use, it would be best to have the 'correct' encoding by grading through the gamma view for your setup while working. "Bright" or shall we say, normal office lighting, go with Premiere's Viewer gamma 2.2 option. If you've got a moderately to pretty dark room, use the 2.4/"broadcast" gamma viewer option.

NO professional media is graded for 1.96 display transform ... so everything you watch on that rig that is broadcast or streaming was graded for b-cast. Dark room, gamma 2.4. Which is what you're used to seeing on your rig. You don't notice it's "lighter" because you never see the colorist's screen, of course.

[t.linn]

Good news. Thank you again for sharing your knowledge, Neil. This has been very helpful.

[R Neil Haugen]

Glad to help ... this stuff is so freaking confusing. And a lot is totally counter-intuitive to boot.