Blackmagic Forum

Hello,

I'd like to use Film Looks->Rec.709 Kodak LUT at the end of Davinci YRGB Color Managed workflow with Davinci Wide Gamut preset and Rec.709 Gamma 2.4 output color space Project Settings.

To do that right, I need to input Rec.709 as Color Space and Cineon Film Log as gamma into a node with this LUT.

When I set the Color Space Transform node before the LUT node to:

Input color space: use timeline
Input gamma: use timeline
Output color space: use timeline
Output gamma Cineon Film Log

the image didn't seem to look right. It had its highlights blown out.

So, I went back to Project Settings, switched 'Davinci Wide Gamut' preset to 'Custom' which displayed its settings. I learnt that the Timeline Color Space for this preset is Davinci Wide Gamut with Davinci Intermediate gamma.

Then I changed to Davinci YRGB workflow and did the color space transform with nodes from BMPCC4K to DWG/DI and then before the LUT node:

Input color space: Davinci Wide Gamut
Input gamma: Davinci Intermediate
Output color space: use timeline (which was Rec.709 for Davinci YRGB Project Settings)
Output gamma Cineon Film Log

the image looked way better than before.

Questions:
1. Why is it that CSR nodes in Davinci YRGB workflow don't do the same as Project Settings in Davinci YRGB Color Managed workflow?
2. Is there a way to set CSR node in Davinci YRGB Color Managed workflow to feed correct data into the Kodak LUT node?


PS:
The post is getting long but here's another thing I checked out of curiosity:

I switched back to Davinci YRGB Color Managed and instead of 'use timeline' settings I entered DWG as Input color space. As I expected that didn't change anything since it was the same as in the Project Settings with Davinci Wide Gamut settings. But when I changed Input gamma to Davinci Intermediate (again this is what you see in the Project Settings preset) the image turned into a mess. Now, this is something I don't understand totally

When I was discussing another topic I noticed a discrepancy between color managed and the CST nodes.

You have to manually set the input space and gamma to DWG/Intermediate because Use Timeline takes the Rec.709 Output spaces instead of the Timeline space from the project settings.

Setting it manually should give the same result as non managed.

To elaborate, I did a quick test with a RED file.

Nonmanaged:
CST: RWG/Log3G10 -> Rec.709/CineonFilmLog
LUT: Kodak Film Look

Managed:
CST: DWG/Intermediate -> Rec.709/CineonFilmLog
LUT: Kodak Film Look
CST: Rec.709/Gamma 2.4 -> DWG/Intermediate

Maybe you forgot to go back to the timeline space in managed. You have to do this because managed has a "hidden" CST that transforms all to the chosen output space so the node tree has to end in the same space as the timeline space.

Thanks a lot for the answer!
It helped

I didn't know I need to add yet another CST node after the LUT is applied in the managed workflow to set it back to the Timeline Color Space. That makes sense, though.

I did a comaparison check:

Non-managed:
Input Color Space: BMPCC4K Film Gen 4
Input Gamma: BMPCC4K Film Gen 4
Output Color Space: Rec.709
Output Gamma: Cineon Film Log
->
Kodak LUT

Managed with DWG preset:
Input Color Space: Davinci Wide Gammut
Input Gamma: Davinci Intermediate
Output Color Space: Rec.709
Output Gamma: Cineon Film Log
->
Kodak LUT
->
Input Color Space: Rec.709
Input Gamma: Gamma 2.4
Output Color Space: Davinci Wide Gammut
Output Gamma: Davinci Intermediate

and the waveforms for both are almost identical