Color Space and Gamma when exporting From Davinci Resolve

[mabdelfatah]

Hello, I tried to find a clear answer for this but it seems like there is no clear answer

I was wondering what settings should I choose for Color Space and Gamma when exporting from Resolve to DCP-o-matic ?
I have ProRes4444 already color graded full film footage, and Resole project settings is Rec.709 Gamma 2.4

I tried different settings (p3, gamma 2.6, rec709A) but none of them show accurate 100% when played in the player , sometimes blacks are dark/crushed , or gamma is brighter/darker, colors are more saturated, etc

what should be the export settings for color space and gamma to get the accurate look as graded without clipping or color shifts?
and what should be the correct settings after importing the footage to DCP-o-matic?

Thanks!

[Carsten]

Stay at Rec.709 with gamma 2.4 in Resolve, and use BT.1886 color conversion in DCP-o-matic. Make sure you use either full or limited range within Resolve (Video vs. Full) AND DCP-o-matic the same. Standard for Rec.709 is Video/limited range.

[mabdelfatah]

Thank you! I tried it but in DCP-o-matic player on my monitor it looks darker, is that normal? Should i be expecting it to look the same as my in Resolve? Or what?

[Carsten]

In Resolve, it's rec.709 or BT.1886. In DCP-o-matic player, it's a retransformation from DCI X'Y'Z' at gamma 2.6 for 14fL/48cd/sqm.
This is meant for a very different viewing environment, that a common sRGB Monitor can not simulate. I don't know if your Resolve installation is color calibrated. In my experience, DCP-o-matic player comes very close, but if you're picky, you may need to evaluate your DCP in a cinema.

You may load your DCP into Resolve and compare it with your master there.

[macg]

Hi everyone,
I understand this thread is 2 weeks old, but I would like to clarify a related information if possible.
I usually leave "same as project" in the Resolve export settings. In the project settings I leave it Rec709(scene). Is that ok? Can there be an incorrect interpretation in DCP-o-matic from this setting?
As far as I understand, this setting only changes the gamma and color spacte tags of the files, not the content itself. Does DCP-o-matic actually reads these tags? Just to clarify, I grade to a proper calibrated rec709/2.4 gamma monitor.
I only recently started doing DCPs, but have learned from someone who did it this way for a long time with no problems apparently.

Thanks!

[Carsten]

When you work in rec.709 or BT.1886 with a gamma of 2.4, BT.1886 in DCP-o-matic is the right choice. Yes, in an ideal world, meta information would always be present and correct, but in the real world, it is not. So, DCP-o-matic has defaults and manual overrides.

Essentially, rec.709 with a gamma of 2.4 IS BT.1886.

[macg]

Hi Carsten,
thank you for taking the time to answer. However, I'm not sure I understand what to do exactly in the Resolve Export setting.
From you reply, I get the feeling that the gamma/colorspace tags don't really matter since inside DCP-o-matic, we are telling the program how to properly interpret the file. Is that correct?
I grade for rec709 2.4 but in the Resolve export setting I usually leave the Color space and Gamma tag to "use project settings", wich means it will apply the Rec709(scene) tags and not the "regular" 2.4 gamma tag. If it does no harm, and DCP-o-matic ignores these tags, I would leave it that way, but I would love some confirmation.

Thank you!

[bcslaam]

I have a similar question and would also appreciate clarification of what settings for export in Davinci Studio 20.1.1, (DR). Which arguably tells us a DCPoMatic universal approach regardless of editing software.

Background
For this project, the colourist sets his colour space (overridden by timeline) to DaVinci WG/intermediate and output colour space rec 709 gamma 2.4, delivered in prores 422 HQ 4k to me as a DR timeline I import (works really well). I always make sure my project and output settings correspond to source anyway.

In the timeline settings he has put data levels at video but recommends I keep DR at auto at export. That's the only difference, but I have tried also at video with same result. Ive have tried two methods of making the DCP in DCPoMatic (latest ver):

1. Exporting from DR a jpg2000 sequence with colour settings at settings same as project. 200mb/sec. Kakadu DCP, 2K DCI, 24fps, separate QT export of audio at 24fps. The DCPoMatic settings automatically end up at BT 1886 on import, no resampling needed.
The result DCP: colours are way off, as in missing magenta in a CMYK space.

2. Exporting from DR a prores 422 HQ at source frame rate, in this case 23.976, 2K DCI, 200mb/sec and letting DCP do the rest. On import it chooses rec709! And at export colours are correct! Sometimes I have to set data manually to Video, because if its Full the blacks wash out etc.

This seems contradictory to your advice to use BT 1886. In DR there is options to set colour space to rec 709 gamma 2.4 as well but I believe setting to DaVinci WG/intermediate allows it to manage all tags so we can leave them at default.

Although unsuccessful so far, I'd prefer to use method 1. Because as a sound post guy I prefer the audio being sped up by changing playback rate rather than resampling. I understand that DCPoMatic resamples the sound instead of just changing the rate tag?

Windows 11 pro, RX4090, latest updates

[Carsten]

Don't export to a JPEG2000 sequence. This is NOT a DCI compliant JPEG2000. This is a common mistake. JPEG2000 is a generic codec, not a specific DCI compliant one. DCI uses very specific JPEG2000 parameters. Only Kakadu DCP Export will create the proper color transformation for DCI compliant J2K.

If your project settings are rec709 or bt1886 with gamma 2.4, just export with project settings. You can set data levels for export in Resolve, if you choose the same (Full 0-255) in DCP-o-matic. This is non-standard, though, usually, video formats use video levels. It depends a bit on the source material and project processing wether data levels are actually useful for an export.

[IoannisSyrogiannis]

Out of subject, but might make discussions easier to follow:
"Da" is a preposition and separate part of the name of "Leonardo da Vinci". That falls into a similar case to "Los" at LA or "Le" at LBJ (LeBron James).
"Vinci", in this case deserves its own letter on acronyms, like "A" on LA, like "B" on LBJ.
When one writes "DR", for whomever knows what that is, the mind is wondering on the realm of the Danish Broadcasting Corporation.