4k to HD path issues
I’m having a bit of an issue with a 4k to hd conversion.
-Program lives on my box in 4k with all the different camera raw clips. Full 45 broadcast show.
-because of the length and complexity of the grade, I have been outputting DPX10 bit sequence files along the way to keep a final rendered 4k version always at hand. If I have to tweak a shot, I simply re-render that shot to the dpx folder, and my dpx output timeline is automatically updated. This prevents me from having to re-render the entire show every time there are tweaks. Has been working well for approvals and promo sections, and all the other output requests…or so I thought.
If I bring those 4k dpx’s back into my original 4k timeline, everything matches up. I can’t tell if I’m looking at the original clips, or the 4k rendered clips.
If however, I switch my timeline down to HD, I have a noticeable difference in shots that utilize a heavy vignette effect. Shots without the vignette are matching up perfectly. (The 4k dpx’s appear lighter in the vignette area than the original shots underneath.)
If I output a 444 4k quicktime movie, I get the same result. Perfect matchup on 4k timeline, but a weaker vignette when I switch to HD.
If I set my timeline to HD, and render out a quicktime, and bring that quicktime back in, it matches perfectly to the original timeline, but obviously not to the dpx or hd downconverted 4k versions.
So what is Resolve doing when it is converting these 4k files down to HD, that it isn’t doing with the original timeline clips? Again, the difference is only noticeable on the vignetted shots, so it is not a full vs video levels issue.
The vignette in question is a stock Boris fx, not a home made vignette created in Resolve. (I may try to test those results as well)
I was really hoping to create a single 4k dubmaster, but I’m afraid i’ll have to make both HD and 4k dubmasters to keep the versions consistent.
any suggestions are welcome.