Discovering a gap in my colmgmt understanding here.
I recently mastered some deliverables from an ACES based HDR project, graded as P3-D65 (ST2084PQ), same as Netflix recommend (though this is not for Netflix).
We now have a delivery requirement for BT2100-2( ST2084 PQ). This project was done with and archived off the machines and servers etc, so this is a new deliverable.
Can I take my existing 12bit MXF delivery exports and input transform them to the delivery spec? Or do I need to remaster from the online exrs (which I would have to restore from archive)
Part of the ACES workflow is an RRT (Reference Rendering Transform). Think of it like a show LUT that is applied to every image. There are chances that if you remaster from deliverables it will not be fully canceled so some strange things may happen. I`d remaster from archives just to be safe.
Just to clarify, do you have a P3D65PQ master? It’s not an ACES mxf? It would be unusual to be outputting ACES colourspace in a mxf but good to be clear on that.
There could be a few caveats to doing this first and foremost. Some delivery specifications demand that no lossy compression has taken place in post production. Working from a 12bit mxf, I would assume it is DNxHR or ProRes of some description which would mean lossy compression.
However, if this is not the case, then you could definitely take your P3D65PQ master and re-export that within the Rec2020PQ bucket. You wouldn’t want to do it from a 10bit source but 12 bit would be ok. Not best practice of course but indiscernible by the human eye. Especially when it will end up being 10bit before anyone at home views it.
So it will really depend on the specifications of whom you are delivering to.
to clarify, we have a 16bit exr aces archive that we can remaster from but its a bit of a faff to bring it all back, so was hoping to avoid this if poss. The’ existing’ masters are 12bit dnx hr P3D65 st2084 pq delivery files. We also made HLGs at the time as well.
so I was thinking import to flame tagged as from file or source, then apply a colmgmt input tranform to REC2100PQ. Feels like it should be ok, but wasnt sure if I’m missing something!
With the caveat that the specifications don’t dictate that no compression can be used, yes, you can import your P3D65PQ master, do an input transform from P3D65PQ to Rec2100PQ and export that and you will be right in terms of colour pipeline. Best practice would be from an uncompressed source but if you’re delivering another compressed format such as DNxHR or ProRes then you won’t have any issues.