Trying to calibrate an LG A1 to 709 gamma 2.4

[Thomasin]

So I tried to calibrate an LG A1 for rec.709 gamma 2.4 and create a 3D LUT for Resolve’s color viewer for test purposes before trying with a larger patch size to create one with the proper BM video card chain. The results however were terrible.

Displaycal settings:

Correction: Tried “none”, WOLED and RGB OLED family, since I wasn’t sure which one’s the best.

White level drift compensation is on

Output levels auto

Profiling patch size 172 since my goal was only test the calibartion prosess

3D LUT settings: BT.709, tone curve rec.1886, gamma 2.4

TV settings:

OLED pixel brightness: 18 (100 cd/m2)

contrast 85

Screen brightness 50

Gamma 2.4

Color gamut set to native but tried auto too.

Color temperature warm 50 (the maximum it can go)

R: 0

G: 12

B: 0

All enchancing features and energy saving turned off

Before the measuring began, I was hit with the message that stated that my black levels were too low and that’s it probably a problem with the levels. I didn’t take a screencap from that one unfortunetly, but I hope you understand which message I’m talking about. I switched Black levels from auto to Full in the LG menu and after restarting the measurement prosess went forward as usual. So I thought I solved that problem, but more on that later.

The calibration prosess went through and the profile self check message appeared: sRGB gamut coverage 82%. On a wide gamut LG with 97% P3 coverage. Not sure what happened there, the gamut was set to native and the only other option was “auto” which gave even worse coverage results.

Also, the results bad all around as you can see in the report. Average ΔE*00 2.79, Maximum 9.48.

First I checked the probe hadn’t come loose, but no problems there. So I tried to play around the TV’s settings, changing OLED pixel brightness setting and gamut but the results were much of the same. After 7 tries I gave up, not least because the “Black levels are too low” message came back even though I don’t think I changed any settings related to it. This time I couldn’t get rid of the message no matter what I tried.

So, any ideas were to start? Would accessing the service menu help? I couldn’t access it with the TV’s remote but I am aware that I probably need an original LG remote or the service remote. But are there any settings there that could make the outcome this bad? Like the energy saving features?

• This topic was modified 2 years, 5 months ago by Thomasin.
• This topic was modified 2 years, 5 months ago by Thomasin.

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[Vincent]

Likely to be HDMI range mismatch, check GPU + OSD settings.

[Thomasin]

You mean the range mismatch caused such poor results or just the message about the black levels?

[Vincent]

“TV full, GPU limited” is likely to cause the desaturated RGBCMY you see in report, CIE ab* 2D plot.
It may have other causes, like messing with TVs CMS, but it seems that TV is on a Rec709 mode with HDMI range mismatch.

[Thomasin]

Okey, thank you for the quick reply!

[Raj S]

For the correction, use WOLED. That is the correct choice for LG OLEDs.

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