Blacks Slightly Lifted in DCP

[lith1ium]

Hi everyone! First of all, just want to say a big thank you to the team working on DCP-o-Matic - thank you for this wonderful piece of software and your hard work, I very much appreciate it! : )

I edited and color graded a short film in Davinci Resolve (Rec. 709 / Gamma 2.4) and I also have a external monitor connected via Blackmagic UltraStudio Monitor 3G that is calibrated to Rec. 709 Gamma 2.4.

I exported the finished film as ProRes 422 HQ, which in Quicktime matches what I see on my external monitor.

When I bring the film into DCP-o-Matic I can immediately see in the viewer that the shadows appear slightly lifted (as well as a greenish tint appears, but that is normal and expected from I understand) I export the DCP using Rec. 1886 and the problem persists.

Dom Viewer.jpg

Quicktime.jpg

I am attaching screenshots and a metadata.xml for additional info. One more detail that could be of help - when I open the ProRes file in IINA, it looks just like in the DOM viewer.

Thank you very much for your help in advance - I'd be very grateful if I can solve this issue and make my DCP look correct.

[Carsten]

rec.709 in DCP-o-matic uses gamma 2.2, bt.1886 uses gamma 2.4 and should be the proper conversion preset.

You will always see slight differences after the conversion - keep in mind, the DCP is not created for viewing in a lit rec.709 or bt.1886 environment on direct view displays, and the color back-transformation in DCP-o-matic player to sRGB can not simulate a cinematic viewing environment.

If you're picky, you need to take the DCP to a cinema, and hopefully to one which has recently been color calibrated.

What happens when you import the DCP back into DaVinci?

[lith1ium]

Carsten, many thanks for your response!

I thought a slight difference is normal as well per what you explained regarding the viewing environments and direct view displays, but I loaded another ProRes master into DOM and for that movie both the DOM viewer and Quicktime looks extremely close. I also exported a DCP for this second movie (with the rec.1886 setting again) - and it looks quite correct in the DOM Player. This second movie was not graded or exported by me.

Quicktime.png

DOM Viewer.png

So this makes me feel like my export is somehow wrong? I noticed also that my file is tagged 1-2-1 in the metadata and the other movie that looks correct has a 1-1-1 tag - could that affect somehow how DOM reads my file by any chance?

Screenshot 2025-03-25 at 17.25.38.png

Regarding importing the DCP mxf back in Davinci - I did it and it looks terrible on my Rec 709 Gamma 2.4 timeline Apologies for the newbie question, but do I need to do some conversion to check if it looks correct?

I also imported the ProRes export back into Davinci and it looks identical to the original color grade - no changes have happened to how the picture looks after export.

[lith1ium]

A small update:

I tried changing the color profile tags in order I match my movie's tags to the one that looks correct using AMCDX Video Patcher but it didn't help. I guess the issue is not with the tags...

[Carsten]

Hmm. I forget to mention the 'range' parameter. Maybe the 444 is full range, and the 422 is certainly limited/video range. Can you try that setting? It directly affects shadow and highlight rendering. Maybe it drops or raises shadows more than you want, but I'd give it a try. Do you know about the video waveform monitor in DCP-o-matic ?

[lith1ium]

Carsten, you hit the nail on the head! I exported a new ProRes 4444 version of the movie from Davinci Resolve and manually set the levels to "full" - now the movie looks corrrect! This was it!

Thank you for your help! : )