- This topic has 1 reply, 1 voice, and was last updated 1 month ago by
.
-
Posts
-
I am trying to profile a Black Magic Design Video Assist 7″ 12G screen in HDR.
I successfully created a 3DLUT for SDR already but the problem is that it’s HDR mode has such a huge “black crush” that I receive an error from DisplayCAL about a TV/PC level mismatch (the levels are correct – as I said, I already proiled and validated the SDR mode). The issue in HDR is so huge that even doubling down on the levels (both the GPU driver and madVR is set to TV levels at the same time, so black should be plenty bright) can’t get around the error message.
I updated the firmware of the device and it doesn’t have any level settings (but again, SDR works as expected).
How could I suppress this error, get the measurements and later fix the huge black crush manually? (I can edit the resulting 3DLUT is Resolve to “fill the gap”, so to speak).
Yes, I could create a “fill the gap” 3DLUT in Resolve right now, profile the display and burn the LUTs then. That would probably be better anyway. Problem is, I can’t output HDR from Resolve at home (I don’t have a DeckLink khardware here and Clean Feed is not HDR compatible). All I could do now is “tryal and error” until I get it right. Well, actually, I could use Resolve’s Clean Feed with a fake HDR metadata injector (an HDFury Integral) but I am a bit lazy to set that up right now. 🙂
However, at any rate, I am curious about how to suppress this error message, just in case I run into a similar trouble later (a manual fixup with a Resolve edited 3DLUT is an option here but that’s not always the case – for example, that would not work with a PC monitor with no 3DLUT capabilities).
Ok, I eventually chose the “correct” route: I manually created a 3DLUT with Resolve that fixes the black crush (I used an HDFury Integral to inject fake HDR metadata to Resolve’s Clean Feed, then I used the curve editor of Resolve to elevate the black level until the first gray bars appeared on the SDR test pattern but black remained black – well, as black as it gets with approximately 800:1 contrast ratio – I had to move the curve by an insane amount, by the way, it’s crazy how BMD didn’t fix this in their firmware yet). Then I uploaded this 3DLUT into the hardware before I started measuring my testchart with DisplayCAL. I will obviously combine the manually created “black crush fix LUT” with DisplayaCAL’s calibration 3DLUT in Resolve once the profiling is done to get a final calibration LUT (which then might be combined with a camera LUT but that’s not my problem).
