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So I’ve managed to create madVR 3D LUTs for my LG OLED in Rec. 709, but I’m very lost with the HDR option. I’m using standard madVR HDR settings, with white level drift compensation on, and process HDR content on — everything else is default. madVR is set to TV levels (16-235). Since my OLED can process HDR content, I have it set to passthrough. For madTPG I select BT.2020, .005 nits, and 1000 nits, and enable HDR (my display goes into HDR mode). Whenever I try to create a 3D LUT, I get an error message that “the difference between 0-16 is below .02 cd/m2… .” (snip attached).
Any help?
Using a Spyder5
Well, the message already tells you what to do: The black level configuration is incorrect, and you’re clipping levels. Set it to 0 nits, not 0.005 nits.
😮 I was doing .005 nits thinking it should match with UHD.
Just did a quick calibration and profile using default settings, and I’ll be redoing it later tonight, but right off the bat the image looks worse than it did with just a passthrough (like the quality loss you get after over compressing a video). Might the default patch size of 175 have something to do with this? Should I increase it?
Also, as far as the target peak luminance goes, would it be OK to increase it having in mind that I plan to play UHD content with full brightness on my OLED (which peaks at around 700cd/m2? Should even be calibrating with such high levels? Am I risking burning-out the sensor on my Spyder?
Might the default patch size of 175 have something to do with this? Should I increase it?
Possibly. Also, make the patch area as small as possible, use black background, enable white and black level drift compensation, and set patch sequence to “Maximize lightness difference” to counteract potential display stability issues.
Also, as far as the target peak luminance goes, would it be OK to increase it
If your OLED can do 700 cd/m2, you can just set that as target.
Am I risking burning-out the sensor on my Spyder?
No. The Spyder5 can read up to 5000 cd/m2 according to DataColor. Even above that, sensor “burn-out” wouldn’t be a thing – the sensor would simply reach its saturation and return inaccurate readings.
So I ran an initial calibration using the same patch size of 175 (to speed things up), but enabling white and black level drift compensation + maximize lightness difference. I set the target peak luminance to 700cd/m2. Everything looks good. Better I might add then without a 3DLUT profile. But I can’t verify anything, because the verification for HDR has me even more puzzled. That plus the fact that my white point keeps changing, so I’m not sure I can even rely on the verification, because it might just be my OLED having drifted from its whitepoint.
I was wondering, given 700-750 cd/m2 is my OLEDs peak at 100% “backlight” levels (which I intend to run at for UHD), but we’re only talking about a 1-10% window, should I be calibrating at 100%, or to more realistic “in-scene” levels? Or this the whole point of white drift compensation?
Just want to add, thank you for helping me out. I’m sure it gets tiring helping mere mortals like us.
But I can’t verify anything, because the verification for HDR has me even more puzzled.
On the “Verification” tab, set testchart to “Extended verification testchart (HDR video, Rec. 2020/P3, SMPTE 2084, 500 cd/m²)” and simulation profile to the tonemapped Rec. 2020 profile that was created alongside the 3D LUT (Email in your case). Enable “Use simulation profile as target” and “Enable 3D LUT”.
Don’t expect great delta E results though, as the limited number of profiling patches over the huge contrast range as well as the nature of the internal display processing limits the attainable accuracy.
That plus the fact that my white point keeps changing, so I’m not sure I can even rely on the verification, because it might just be my OLED having drifted from its whitepoint.
The measurement report evaluates white point independently from colors, so it can still be useful.
should I be calibrating at 100%
Probably yes. Only that way, the response of the HDR highlights can be characterized.
Just want to add, thank you for helping me out. I’m sure it gets tiring helping mere mortals like us.
That’s what the support forums are there for. I just sometimes wished people in general would use the search more often (not aimed at you though, this is one of few HDR-related threads so no repeating myself syndrome yet) 🙂
