I understand your concerns but DLog-M is not really a true log encoding. So it isn’t as simple as defining a log to linear function. As far as I’m aware it is also tuned per camera depending on the sensor capabilities. There wouldn’t be a single IDT possible.
What DJI could do is provide custom LUT based DLog-M to linear conversions per camera. But this may simply not be on their agenda as the see DGamut/DLog as the premium/pro option. But that’s my wild guess. Until then you can try your luck with that IDT I linked that someone made or flag it as Rec.709 and work from there.
I am currently working on an HBO show as DIT and Dailies Colorist. Our Drone Unit shoots DJI Inspire 3 8k Cinema DNG Raw. I would like to grade this footage in our Aces 1.3 pipeline and then render the results if possible with ProRes intermediates.
So what I tried is to render all my 8K Cinema DNGs to a 2K ProRes 422HQ intermediate - without grading, just log.
Then I would apply “No Aces IDT” to those intermediates and the DLog_DGamut_to ACES_AP0.clf from the DJI website. Unfortunately the results don’t match.
Someone has a tip for me how to get this to work?
The idea behind the workflow is to shorten the rendering time when the grading is done.
The workflow works perfectly finde with our Alexa 35 footage and also with our Ronin 4D footage (though shooting ProResXQ so this is easy).
So I tried to add an ACES transform before the grade on the intermediate: “No input transform” => “ACEScct CSC.” Still not matching DNG Raw + Dailies Grade.
But anyway - just asking - since my Project Color Management (see screenshot below) processes Nodes in “ACEScc AP1 timeline space” - shouldn’t I be fine even without this transform?
To broaden the question: Do you have an idea how I could get this to work? avoiding to have to render the dailies graded material from the original 8K DNG Raw OCF and somehow use a prerendered more lightweight intermediate instead?
When you’re creating the mezzanine files, is your Resolve project’s Color science set to DaVinci YRGB or in ACEScct?
In ACEScct, Resolve will map the DNG (from who knows what, conceivably Rec.709/sRGB or Rec.709/Linear) to ACES AP0/Linear. By the numbers. (No D-Gamut / D-Log involved)
In DaVinci YRGB (i.e non color managed), Resolve defaults to Rec.709/sRGB. Not D-Gamut / D-Log. The official DCTL is not meant for DNG imagery, it’s meant for H.264/ProRes/etc capture.
Thank you very much for your detailed answer—and sorry for the late reply.
Especially the +1.4 exposure hint is very interesting. When writing my question, I should have mentioned I was creating the mezzanine files from Silverstack Lab. Indeed, they match pretty well (differing a bit in the highlights, maybe even good enough for the purpose of an ambitious dailies grade) when I set the DNGs in Resolve to Exposure +1.4.
Since I am on an ongoing project, I didn’t want to change this in the middle of production. Following your suggestion, I am now creating the mezzanines for the Inspire footage directly in Resolve, converting them to ACEScct.
I am considering, though, using the +1.4 exposure as a standard approach for my next project—even though I am not sure if this could cause trouble for VFX pulls if the drone shots and LUTs no longer match the references.
