Rec709 GFX in HDR using DoVi

Hi there, using Flame2023 project created in legacy colour policy. Working with sequence: DPX UHD HDR in PQ_P3_1000nits supplied from Baselight with a DoVi trim.
All graphics supplied are in Rec709 and layered in timeline. Using input colour management: input colour space [Rec.709] video to Working Colour Space [Rec2100,PQ] and with a colour correct adjusting gain.
I noticed a hue shift on reds which I can correct the with CC.
What is a concern in SDR is how the DoVi is affecting the GFX when used across multiple shots and the trim changing the look of GFX in SDR.
How do you manage this to keep the GFX colour consistent across multiple shots in time line in SDR. Is it standard approach to adjust the DoVi trims to balance the GFX. Would great to get some feed back on this when possible.

Are you delivering a Dolby Vision Master or separate HDR & SDR masters?

If separate HDR & SDR masters, I use one layer underneath my Dolby Metadata to add all my HDR graphics. Then I have another layer above the Dolby Metadata with my SDR graphics. I then hide whichever layer isn’t being used in mastering.

As for when you are delivering a Dolby Vision master. Unfortunately, for the SDR version you will either need to compromise on having the graphics shift luminance/chrominance between shots, or you adjust trims to keep the graphics right but then that would be compromising the shot the graphics are going over. I tend to try and time graphics in a way that it doesn’t spread across multiple shots but that is not always possible. In those cases I just live with the graphic shifting slightly. There isn’t too much you can do about it to be honest.

What I would like to see is graphics being a separate layer/element in a Dolby Vision IMF delivery so that the graphics would not be affected by trims but that isn’t going to happen anytime soon.

Hope that clears things up.

I might be missing something, but if you have graded to and are delivering in P3/PQ, I think your Working Colour Space (and tagging of HDR material) should be ST-2084 (PQ), DCI-P3 (D65 white). What Flame calls Rec.2100 PQ is actually Rec.2020 colour primaries, not P3, which may account for your red hue shift?

What @AdamArcher said about the rest of it. Or hand the GFX back to Baselight and make it their problem!


thanks for the response guys.