Davinci YRGB to Resolve Color Management (and Camera Raw)

Hey Folks,

I have searched the manual, forum and several YT-Videos, but I can't figure this out:

When I swap from Davinci YRGB to RCM there appears a color shift in external viewer (via Intensity Pro 4K) and scopes even before any corrections to the footage are made. The only way to avoid this seems to be to bypass the input color space for the individual raw clips, then in the camera raw tab set the color space to the option it was decoded to before rcm and to deactivate the color space aware grading tools.

So for raw clips how does Resolve interprete the info from the camera raw tab? Aka:
It doesn't change anything if I change the input colorspace for a raw clip, as these are decoded directly into the timeline color space, but now if I bypass the input color space completely for those clips and change the output color space, they are still affected, as well as when I change the color space in the raw tab i.e. I am not bypassing the entire scene-referred workflow but only the first part. However, how does Resolve go about going from the color space I set in the camera raw tab to the timeline color space? Or: what is the camera raw tab doing in a Scene-referred workflow with input CS disabled?

Cheers and thanks a lot for the insight

Wolfgang

I think the issue lies in your idea that switching to a different management system shouldn't change the resulting image output but this is not true.

Working with raw files unmanaged will usually have the management system from that vendor for mapping to display space. This is what you can influence in the Camera Raw tab.

When you switch to RCM you basically let the DaVinci management system take over and manage the incoming data and output mapping locking you out of changing it. The DaVinci system allows you to work in a preferred timeline workingspace and the output mapping is managed afterwards making it viable for multiple display deliveries like SDR and Cinema or HDR and using mixed camera footage without having to convert them individually.

Using DaVinci as the Input DRT also allows you to take different sources and automatically manage them to get a perceptual uniform result without using conversion luts which are limited to a single display referred input like rec.709 and only provide a transform to a single output.

So in overview what's going on is:

Input DRT: DaVinci
Manages all sources and converts them to chosen timeline workingspace.
For supported raw formats and files with metadata like Arri, this happens automatically. For log formats in ProRes e.g. you have to manually select what the Input Color Space is for that file from the bins.

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Output DRT: DaVinci
Maps the timeline workingspace to chosen (display)output space.
The way this happens and how it looks is engineered by Blackmagic Design to provide the best result to their vision.

That's pretty much the power of using RCM. The 'default look' it gives shouldn't put you off. It remains a starting point to infinite looks and there's no loss in data working like this over non-managed.

Working with ACES is very similar to this but will also give a different default look because they map it differently too.
And they aren't the only one. Arri has K1S1 and there's T-CAM from Baselight and lot's of others.

You can even use RED's IPP2 as output mapping system inside Resolve if you select that instead and it'll give you yet another result.

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Hope that makes sense.

Or: what is the camera raw tab doing in a Scene-referred workflow with input CS disabled?

Forgot to answer this but the Input Colorspace setting is only for any footage that doesn't have it's Input automatically or manually assigned. Only useful for deciding what Resolve interptrets any non-tagged footage with. It doesn't influence raw files because Resolve knows the native source colorspace and takes it in as linear data.

your idea that switching to a different management system shouldn't change the resulting image output but this is not true.

This was my first thought as well.

Ok, to get this straight: I do understand how RCM works - that's the point of it all (in fact I would even argue, that, as a semiconductor phycisist, I do even understand quite the origin of scene vs display referred color spaces and workflows). I feel I don't fully understand how DaVinci YRGB works

So first of all, thank you, shebbe for going through it once more for me, but - I assume I have expressed myself badly - that's not really what I was trying to figure out.

So first of all, if I operate inside the same timeline color space, by chosing my input and output DRTs accordingly this is exactly what I should get: the same image as in a non color-managed workflow as the grading tools will behave exactly the same. So my first question merely was: how to choose those to mimic what Resolve does in a non-colormanged workflow. The answer is: bypass input color space.
Because, apparently then it stuffs the original data into the timeline CS unprocessed (or at least in the same way as in the non-managed workflow.

And this is what prompts my second question: what does the Camera Raw tab do in relation to the timeline colorspace? Since here I can pick different color spaces and those apparently serve as sort of input color space (which then ofc. only works if the input colorspace is disabled).
Now I do understand that the beauty of the beast is to explicitly NOT have the input colorspace for raw data but to decode it straight to the timeline color space. However, I oftentimes find it more pleasing to decode the raw data with a less logarithmical gamma curve (e.g. BMD E-Video or Video) since this get's me rid of a big part of the normalisation effort. Hence, I often stuck with a display-referred workflow in the first place when I had only one destination and type of input media (braw).

Now for some projects it occured to me that I might want to use them in other applications than the one originally produced for (e.g. a short film i was working on recently) which is a little more comfortable if i only need to change output CS and my displays calibration and do some timeline-tweaks. Accordingly my workflow for those older projects now is:

- swap to RCM with same timeline CS as chosen in DaVinci YRGB
- bypass input CS for all raw clips, keep camera raw tab as was before, set Rec.709, 2.4 for everything else
- set output CS to desired CS, accomodate for output-drt color-shifts in a timeline node.

Please let me know if you think this is a reasonable approach (for most new projects i do use RCM with wide gamut by now, but older ones want to live up some times, too )

Once more thanks for your input and have a nice day!

Cheers

Wolfgang

As I understand it, Color Space Transforms (CST) translate their Gamma and Gamut first to Linear and XYZ, and then to the desired new Color Space.

That is why I use Linear/CIE XYZ for the timeline.

First, I "develop" RAW to the widest Gammut/Gamma available. In some cases that is direct to Linear/XYZ, but each RAW format has different options in Resolve.

Then, I use a CST before the first node to transform the RAW settings to the timeline (Linear/XYZ).

And finally, I use a second CST to transform from the timeline to the chosen output, e.g. 709/709.

This works quite well. It is a manually managed approach. Each RAW, or not RAW, clip can have it's own CST. And they can all be on the same timeline.

Resolved Managed and ACES are fine, but they allow limited control, and there are many cases where they just don't work well.

Apologies if I've misjudged your expertise.

I think I kind of understand what you're getting at now but I still might be wrong haha.

Your main goal is to adapt your existing DaVinci YRGB projects to RCM for future flexibility without changing the creative intent?
This would include perserving chosen colorspace and gamma settings in the Camera Raw tab by not having RCM manage the native camera data directly to chosen timeline working space.

But doing so results in a color shift?
As far as I can see this is only because of the colorspace aware grading tools checkbox.
Disabling it gives me the same results. Just tested this here with some .braw sample footage and I don't see a noticable shift in the viewer keeping RCM at SDR100.
However I do see a change in incoming data in the scopes but not sure why.
Maybe you know more about this than I do hehe.

I think what you explained, keeping the raw files as bypassed to manually keep 'em like unmanaged raw settings is indeed the solution.

For future projects it would just make sense to instantly use RCM and have your chosen output transform be your visual starting point already instead of BM extended video etc but set your timeline to DaVinci WideGamut or whatever you'd prefer non-display referred

That is why I use Linear/CIE XYZ for the timeline.

Interesting. But isn't working in linear very 'unpredictable'? I mean not for compositing but for colorgrading.

I do like the idea of managing everything yourself though and I hear lots of others doing the same to maintain full control of how stuff goes in and out but at the same time it can be a lot of stages where issues/human error might arise especially when you're dealing with big projects and lots of different sources.

Interesting. But isn't working in linear very 'unpredictable'?

Not really, especially if you use RAW controls. I find I'm 95% there with just RAW controls.

The math is all linear.

Apologies if I've misjudged your expertise.

I think I kind of understand what you're getting at now but I still might be wrong haha.

Your main goal is to adapt your existing DaVinci YRGB projects to RCM for future flexibility without changing the creative intent?
This would include perserving chosen colorspace and gamma settings in the Camera Raw tab by not having RCM manage the native camera data directly to chosen timeline working space.

But doing so results in a color shift?
As far as I can see this is only because of the colorspace aware grading tools checkbox.
Disabling it gives me the same results. Just tested this here with some .braw sample footage and I don't see a noticable shift in the viewer keeping RCM at SDR100.
However I do see a change in incoming data in the scopes but not sure why.
Maybe you know more about this than I do hehe.

I think what you explained, keeping the raw files as bypassed to manually keep 'em like unmanaged raw settings is indeed the solution.

For future projects it would just make sense to instantly use RCM and have your chosen output transform be your visual starting point already instead of BM extended video etc but set your timeline to DaVinci WideGamut or whatever you'd prefer non-display referred

YES to everything you said, especially new projects going color managed right from the beginning - unless i want them to be done fast, then I'll just start from extended video or video in the raw tab and go from there! (except the thing about my expertise - one never stops learning and this discussion [and having to write up the process myself] helped me tremendously wrapping my head around it^^):D

Also, the color space aware tools pose a potential threat, indeed, if the footage is adjusted already,y.

Once more, thanks for the discussion and: if anyone can tell me how resolve mapps the chosen input color space (raw tab) to the timeline color space in the non-RCM workflow, I'd love to hear (merely out of curiosity as I don't feel it affects how I work if the workflow is display referred anyways, but it'd be nice to understand).

Interesting. But isn't working in linear very 'unpredictable'?

Not really, especially if you use RAW controls. I find I'm 95% there with just RAW controls.

The math is all linear.

Even though I like the approach in principle, there're two issues I have with it:

1) it seems quite tedious to manually manage all individual clips with CSTs, compared to RCM, but since that's what most of us have done before, too, I guess my objection isn't really valid

2) Ctrl+z doesn't work in the raw tab (at least for me) which makes it cumbersome to copy-paste grades on the fly if the raw-tab is changed, too. So if the footage is shot well and I don't need to fix wb or similar I like to leave the raw-tab unchanged or make the same changes to all clips (at least in a group) there so i can quickly copy&paste the grades


Cheers

Wolfgang