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Question

There must be a way of more accurate colors after rendering?

Forum|Forum|1 year ago
September 3, 2024
2 replies
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For as many years as i remember, i've been frustated with the colors i get out of Premiere - to the point where I kind of gave up.

I started working now in DaVinci that easily renders out files that looks like expected on webdevices - which is, let's be honest, what most content are going to these days.

In DaVinci i can set the color space to sRGB and change gamma to DCI-P for instance. This makes it look great on iPad, iPhone, Laptops etc.

However, my struggle is endless. Working on a color accurate project in Premiere now, that can't be conformed and go to DaVinci, but the colors looks absolutely off when rendered out.

Are there really no way of choosing what color space etc. you are rendering out in? I understand that Premiere is made with broadcast in mind, but this is an unfathomable outdated mindset for how media is used these days.

I hope i overlook some simple settings.

cheers!

This topic has been closed for replies.

R Neil Haugen

Legend

I work for/with/teach pro colorists. I'm in both Resolve and Premiere daily, just completed a training tutorial for colorists on how to use Tangent's new "Warp Enging" part of their Hub maaping system to allo mapping more Resolve controls to Tangent panels ... demonstrating use of both the HDR palette and the Color Slice tools completely mapped to the panel. So I've a bit more than "some" experience in both Resolve and color management.

First, getting appropriate expectations is key. "Accurate" color doesn't actually exist ... that is, if you expect any two screens to show the same image, well ... that's been proven impossible many times by both colorists and color calibration specialists. You cannot completely match two "identical" screens, side by side in the same room, calibrater and profiled by professionals, and fed the same signal.

The entire reason for grading "to the standard" isn't for broadcast or streaming specifically. It is simply so that your produced media, on any screen out there, looks in relative terms like other professionally produced media on THAT screen for THAT viewer.

As has been stated for years ... "you can't fix grannie's green TV" ... and granny doesn't even realize it's way green.

I've just been quoted around the Web for a comment I made on a pro editing program ... passed around by several noted experts and colorists. It's about how no camera actually records color data ... at all. They record brightness data, period. Then because there is a color filter grid over the sensor, they use complex math to compute 'color' ... or more specifically, hue values.

Then devices take the color data, apply it through through their mathematical processing, and display it on their screen.

However, every step of the process includes imperfections. No two filter grids are exatly alike. No two sensors, off the same line, are perfectly identical. And the mathematical calculations always include both "technical" ... and aesthetic! ... choices, at all levels. Cameras and screens.

So the best we can hope for is roughly equivalent values being displayed. That's something that far too few people understand. And is why it got widely quoted.

However, Apple threw an unfixable kink into the already somewhat muddled screen display situation, when they applied the camera transform function, essentially gamma 1.96, to the display transform function in Rec.709 video. For apps that allow ColorSync to manage (or mangle, as is the practical result) Rec.709 video. Such as QuickTime player, Chrome and Safari Browsers. (But not VLC, Potplayer, or Firefox, which properly ignore ColorSync.)

The Rec.709 standard, for years!!!!! ... has been specified as a function essentially similar to gamma 2.4.

You cannot get the same viewed image with two widely varying display gammas.

And the even "cooler" thing about this mess is ... Macs with Reference modes, set to HDTV, show the correct Rec.709 display transform! So they don't match with Macs without Reference modes!

So Apple devices aren't even consistent with each other.

So are you talking about color in general, or ... across Apple and non-Apple devices? As they are two different subjects entirely.

Next, it doesn't sound like you have a solid familiarity with the color management of Premeire's 24.x series, as if applied correctly, there isn't much problem. And that is across a wide swath of media and workflow needs. Both SDR and HDR workflows, including all sorts of log and raw media, are quite solid. For most media and needs, though not all.

And you can choose whether to work for the 'Apple view', by using the Premiere viewing gamma setting of 1.96/QuickTime, or the standard for all other screens, by choosing the appropriate viewing gamma within Premiere.

If grading in a moderate to bright room environmemt ... then use the mis-named gamma 2.2/web setting.

If grading in a darkened room, with a calibrated monitor set to 100 nits brightness, which is the professional colorist standard, then use the gamma 2.4/Broadcast setting.

Because by the standards, it is your viewing environment by correlation of ambient brightness to screen brightness, that determines using 2.2 or 2.4.

And as Premiere now allows for auto-detect log and auto tonemapping, most log and nearly all HDR media can easily be worked with in either SDR/Rec.709 or HDR, in either HLG or PQ color spaces.

As noted above by the staffer, in the 25.x series, now in public beta, and which will become the "release" version the first day of Adobe MAX in October, there are massive new changes.

Including the ability to set your choice of several wide-gamut working spaces, while viewing and delivering to SDR. And the 25.x Lumetri controls are now color-space aware, and so work befitting the working color space if you choose, not the displayed color.

It's really some awesome improvements for experienced colorists and maybe 5% of the editors out there ... and I'm gonna be busy helping many people totally confused by the new options, and working from idiots on YouTube that can't get their Mbps straight from their MBps, let alone understand how the basics of video color actually work. In practical terms.

Everyone's mileage always varies ...

Viktor slothAuthor

Known Participant

Dear Neil,

Thanks a bunch for taking you the time to pour out all your wisdom.

I, too am an experienced colorist and editor and everything you write makes total sense for me. Thank god!

So as I am entirely aware that no devices look the same, and even though first thing I do when visiting my parents is to turn off all "Color saturation X-Treme" or "Dynamic ULTRA range smooth motion" settings on their TV, I know I can't turn that off on the entire populations devices.

But what I am addressing here is a change that is a bigger difference than that, and that is more relevant to newer challenges. Hear me out:
So first the symptoms: I see a lack of depth in colors and a pretty apparant hue shift when rendering from Premiere and check on my iPad and phone. I did the same as well with DaVinci, until I realized that most gallery apps on phones, and Instagram actually reads video in sRGB and for whatever reason, setting the color tag to P3-DCI seems to do the trick.

Now, with these settings applied the video's look deeply saturated, vibrant and with no hue shift across iPad, iPhone, Android and my laptop. Sure, now we have the "every display is different" but it's negible.

So, I said I was a pro, too. And that is true, but in my career I have mostly worked on commercials - mostly big fashion brands - that exclusively are shown online and on devices, via Tik-Tok, Instagram, YouTube, etc.

And here this issue has been an enormous challenge time and time again. Often when projects are larger, premiere projects are then conformed into DaVinci for grading - but often times - like now, I work on a personal low budget project and would rather not deal with that.

I hope i made it all clear what my troubles are.

Oh, and yes! i downloaded the beta - it does crash a bit - but I saw the options and tried some renders. Unfortunately you can't really choose any output gamma tag and color space tag - at least nothing other than ACES and the rec variants. Right?

R Neil Haugen

Legend

Yes, I thought the Apple mess might be central to your issues. And with your background, I can get more granular.

Apple's mis-application of display transforms is a double whammy.

First, the tonal issue I mentioned in the above post, using gamma 1.96 rather than 2.4 for the display transform. Which would be bad enough. But wait, there's more!

The second part is an imperfect color transform from sRGB media values to the Retina P3 display color space. Which a colorist I follow explored, and demonstrated there are predictable, consistent variations from a "correct" sRGB to P3 transform. Using color model images, so you could see the rotating hexagon or cube hue mappings and compare "proper" and what actually happens.

He knew there had to be something other than the tonal, and went hard after probing the hue value changes. It's amazing work, and explains how the "saturation" problem is actually a color mapping problem, and can't be totally solved by simply lowering or raising saturation. The color, even at correct brightness, will still not be hue-correct.

The 'tagging' thing ... using the NCLC tags ... is also an imperfect attempt to fix things. As no matter how you tag them, some devices/screens will use the tags, many won't, so there is still no freaking consistency

I don't own any Apple devices. Naturally, a goodly percentage of the colorists I work with are total Apple geeks. Yet they are furious at Apple over this mess. They've all tested every possible means to 'fix' this mess. It ain't fixable.

So ... many have newish moderately high-end iPads, the ones with controllable color, as they found that certain models could be matched pretty closely to their reference monitors. And they provide those iPads to clients, with the stated requirement!!!!! ... that all requests for color/tonal changes come from either viewing those iPads in a moderately dark room, or in their colorist suite.

What to do in Premiere for repeatable color?

First, for most users, Display Color Management should be on. Unless you have a fully calibrated and profiled reference monitor. And I typically note that if you don't know the difference between calibration and profiles, you probably ... don't.

This setting makes Premiere look at a monitor's ICC profile, and attempt to match on that monitor the correct values, for any chosen sequence color space.

Next, for the majority of workflows, auto detect log and auto tonemapping should be on. They are interactive, and will map log and HDR media to either HDR or SDR/Rec.709 sequences. Having one without the other, unless you know specifically why you are doing so! ... can be troublesome.

Specific professional workflows may require one or the other set. But most amateur/YouTube (which can also be highly professional) workflows will suffer with only one set to on.

Tonemapping, for information, is an algorithmic mathematical process, NOT a LUT. It is far more complex than any even 3D LUT, and for most uses provides a very safe transform of your pixels, to a very good place for starting color corrections.

Yes, it will look different than a LUT you may have been using, as should be expected. As there is no 'one perfect look/transform' for any media from any camera or device to any disply space. ALL such transforms involve both technical and aesthetic choices. As has been so often pointed out, purely coorect "technical" space conversions always look ugly as sin. They never work visually useful.

So as with any previous workflow, the tonemapping is a replacement for LUT based transforms as a first step in working the clip's visual appearance.

SDR/Rec.709 sequences and exports are still more common, as ... all HDR is still the Wild Wild West. Most of my colorist friends really want to leave SDR behind, but at this time, the numerous competing HDR forms ... all imperfectly adopted by nearly all screens that can do any of them ... frustrate them no end.

As no matter which HDR format you choose to export in, many screens won't do it at all. And among those that do, most slaughter it (to colorist's visual perception) ... yet, when displayed nicely ... oh ... my. And therein lies the problem ... we all want the "oh ... my ... " view for our productions, but so rarely get them.

You and I will enjoy 25.x's greater working space options, but I gotta say again ... there's gonna be a HUGE rush of posts saying "what the HAY????? is going on here?" when it hits the public release phase.

Everyone's mileage always varies ...