Originally Posted by SamuriHL
Yeah this one surprised me, too. Especially where it works on the shield and not the ub820. The only other thing I can think of, and can't see how this would matter either, is that I'm calibrating on a different hdmi input than I use for playback. But after the calibration I do the apply to all inputs to make sure the settings match. I'll play around with it today and see if I can troubleshoot it so we can make a note of it for anyone else who wants to try it.
I'm just grateful to get this working and the calibration looks really good. The de is pretty high though. Like average a bit over 5 for both grayscale and color. Both spike max over 10. Even so it's improved over default.
Thanks again for your help on this. I was starting to give up on getting this to work and now am really happy I can work on improving my results.
Sent from my SM-G975U using Tapatalk
I believe you said you calibrated Cinema Home? You are never going to get anywhere near accurate post calibration greyscale results when calibrating that mode. The Cinema Home picture modes in both HDR and Dolby Vision do not follow the PQ EOTF curve. Luminance is boosted as it is intended for a brighter viewing environment. So when making adjustments with "Enable Calibration" checked, and DV metadata set to "Relative", the results will look good. But when you uncheck "Enable Calibration" and set metadata to "Absolute", you are no longer taking measurements based to 2.2 Gamma, and the TV's internal processing is boosting luminance above the PQ EOTF curve and is likely why you are seeing those high averages and spikes in post cal greyscale results.
The following is something I have messed around with that you might want to try if you are spending some time experimenting. It will initially take a long time, but could potentially save you some time in the long run.
When performing AutoCal in HDR or DV, initially set the the dE target a little higher so that the automatic adjustments are made in a fairly quick manner. Something like dE 1.5 - 2.0 should finish pretty quickly and give a reasonable baseline to work with further. Leave pattern insertion at the default set values for now.
When AutoCal completes, set some really aggressive pattern insertion levels. When I did this I set 3/25/0 which means after 3 seconds of readings a full 0% black will display for 25 seconds. This will counter the luminance boosting significantly when bright white patches are displayed for long periods in HDR. You can set this slightly less aggressive if you like, just make sure you set it to something that allows the panel to fully cool and settle between reads.
Then hit "Read Continuous" and make adjustments using the DDC controls to reduce your dE values manually. As you work you way down the greyscale towards the area outputting luminance in the SDR range (100 nits) then you can adjust the pattern insertion levels to something less aggressive, e.g. 25/5/0, and continue to tweak.
Once done, hit "Read Series" to confirm you tweaks were successful, and if you are happy with the results make sure you take a screenshot of all the values within the DDC panel
Continue your workflow as instructed on screen.
Now, whenever you want to either calibrate another HDR/DV picture mode, you can set the initial dE values in the greyscale AutoCal as high as you want to ensure the AutoCal runs as quickly as possible, and then manually use the DDC panel to insert the values from the screenshot you just took, because all HDR/DV picture mode greyscale adjustments are based to the same 2.2 Gamma before the TV's processing converts it to PQ EOTF.
I can confirm I have tried this several times over the past 2-3 weeks on my C9 and found it to work repeatedly well, with some very minor adjustments being required at times which takes just a few minutes. I can also confirm that when doing this and spending extra time ensuring the very low luminance portion of the greyscale is as good as I can get it with an i1d3, I do not see any raised black issues reported by others in HDR Cinema or HDR Technicolor.
This is not for everyone as some do not have the time nor patience to try such things, and of course YMMV, but it has worked for me and might be of some use to others too.