How to seamlessly integrate different codecs in a Final Cut Pro HDR library
What is the best work flow for seamlessly adding a color corrected Rec709 mastered clip into a HLG 2020 FCPX Library/Project?
The challenge: Camera 1 recorded in S-log 3 Cine which has a STD gamut Rec-709 color profile. Camera 2 was set to HLG BT 2020. The library and project are both HDR/HLG. It is proving extremely challenging to color grade the two clips so that they match each other.
Workflows Used:
Workflow 1: I first tried color grading the S-log 3 footage within a HLG Library/Project. The S-log 3 cine LUT and HDR Tools were applied and set SDR to HLG 75%. Even after the color grade, there was extensive color distortion visible to the eye and in the Chroma Waveform Spectrograph. I also tried turning off the LUT and the HDR Tools feature. Reducing the SDR to HLG 75% setting to 69% helped a bit. I also experimented with Color Curves and Hue/Saturation Curves to see if I could tame the chroma distortion. The end result looked okay in FCPX, but when I rendered the project and tested it on different devices, there was significant color and lighting distortion.
Workflow 2: I did some research and discovered that S-log 3 Cine is not HDR, but rather SDR Rec 709. So this time I created an SDR library and color graded the S-log 3 Cine clip in a flash. Again, I used the Sony LUT. Once I was happy with the color grade, I rendered the clip as a Master file. I then imported the Master file into the HDR Library/Project and added the SDR tools and set it to SDR to HLG 75%. Frustratingly the SDR and HLG footage still did not match. Within the HDR project, the SDR clip now had way too much contrast and all the subtle gradations of greys and color were lost.
Is there another workflow someone can recommend? At this point, I've come to the conclusion you cannot mix S-log 3 Cine SDR footage with and HLG HDR footage in the same Library or Project without significant color shifts.
PS I don't plan on using S-Log 3 ever again. HLG is so much easier to work with.
