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Hi everyone,
I am trying to calibrate a LG OLED 55C7 with a 3D lut going through a blackmagic converter (my target is rec709 gamma 2.4)
It seems that I must have the wrong settings because the Profile Self Check Delta e is very high. And when I apply the lut, some colors gets crushed and the blacks get too high.Profile self check delta E*76 average is 0,81, maximum is 22.51, RMS 1.54
gamut coverage 99,6%RGB ; 87,7%Adobe RGB ; 94,8%DCI
gamut volume 143,5%RGB ; 98.9%Adobe RGB ; 101.6%DCI
Here are some screenshots of my settings. Any advice please ?
Thanks a lot in advance, and thanks for this awesome soft.Hi,
you probably have to use full field pattern insertion due to the LG OLED’s aggressive auto-dimming.
Also, set tone curve on the calibration tab to “As measured” when creating a 3D LUT.
Hi Florian,
First of all, I couldn’t thank you enough for this piece of software and for your feed-backs : just amazing. I cannot imagine the amount of work behind it.
Between my original message and your answer, I did another calibration with the tonal curve set to “as measured” in the calibration tab, and I set the patch chart with the option “maximize lightness difference”, which seems to do the job regarding the Asbl dimming. I’ll do another test with the full field pattern and see if there is any difference.
All the settings and results are here : Calibration LG
I’ll be happy to have your opinion on the results of the verification, which seems good to me.
I loaded the 33x33x33 cube lut in a Blackmagic converter and it seems to work well. Except in the very dark shadows where it tends to create some banding with a green tint (on some very low lighted faces it was clearly visible). Is there any advice on that aspect ?
On another topic I made a calibration of my Flanders DM250 to perceptually match the LG and the results doesn’t seems to be that good. I don’t know if I missed something somewhere.
I choose a white point target by adjusting the flanders (hardware adjustment), then I noted the white point coordinates using the manual white point measurement, finally, I set the flanders back to the default values and choose the white point values previously noted as a target in the calibration tab…then run the profiling and exported a 3D lut…
All settings and report here : FSI CALIBRATION
The white point in the report doesn’t match the target, neither the gamma. So I probably did something wrong somewhere. Beside, I am not sure I fully understand the verification process made just after the creation of the 3D LUT. How can it verify the efficiency of the 3D LUT created if the LUT is not loaded in the monitor ? Does it verify only the profile with the monitor ? Is there a way to check or to make another profile of the monitor once the LUT is loaded to check if it matches ?
Again, thanks a lot ! I am pretty sure that some of these infos are already in the very prolific documentation and I might be a little confuse about these things. I’d really like to get a more clear view of the all process.
Hi,
All the settings and results are here : Calibration LG
I’ll be happy to have your opinion on the results of the verification, which seems good to me.
Indeed, a good result.
I made a calibration of my Flanders DM250 to perceptually match the LG and the results doesn’t seems to be that good
All settings and report here : FSI CALIBRATION
The white point in the report doesn’t match the target
If you do not adjust the TV to match the chosen whitepoint target, then the rendering intent on the 3D LUT tab needs to be set to abs. col. + wtpt scaling.
I am not sure I fully understand the verification process made just after the creation of the 3D LUT. How can it verify the efficiency of the 3D LUT created if the LUT is not loaded in the monitor ?
That is relatively easy. After the 3D LUT is made, you can just “push” random input RGB triplets through the LUT and check whether a lookup of the 3D LUT output RGB values values through the profile matches the target CIE values (and the target CIE values are obtained by a lookup of the input RGB triplets in the target colorspace, e.g. Rec. 709).
Hi Florian,
Thanks a lot for all these infos. Very clear !
Regarding the Flanders situation, I tried to follow the FAQ. These two paragraphs and mostly the second one :
You can use the visual whitepoint editor of DisplayCAL to have a nice, distraction-free white patch on each display. Afterwards, calibrate and/or profile the adjusted display normally (it is important to set the whitepoint target for the adjusted display in DisplayCAL to “As measured”, and if you’re creating a 3D LUT, setting the 3D LUT rendering intent to “Relative colorimetric” so that calibration or the 3D LUT do not change the whitepoint).
If one or more of the displays do not offer sufficient whitepoint adjustment controls, you can use the visual whitepoint editor to do the adjustment in software instead. The process is almost the same, except that after you have achieved a visual match, you hit the “measure” button to measure the white and set it as calibration target instead of using “As measured”.As there is no reference to any difference regarding the Lut creation process, I put it in Relative colorimetric eventhough I didn’t want to adjust the monitor… but understood. Next time absolute + white pt scaling
I’ll run another calibration session next week and let you know.
So far my main concern is the greenish banding in the very dark shadows, that was present in both screens after calibration… I am wondering if it can come from the probe or if there is any setting to increase the precision with the low light patches.Thanks again and in advance : Happy new year !
So far my main concern is the greenish banding in the very dark shadows, that was present in both screens after calibration
I have heard other LG owners mention this (not calibration-related), and it seems to be an issue on some of their OLED models. Some of the LG’s internal controls seem to interact poorly with picture quality, so if you have adjusted anything other than peak brightness on the display itself, try resetting all other color/picture related controls to default values.
I’ll try that. I am afraid though it is related to the calibration because I don’t have the problem when the LUT generated is NOT applied and I had pretty much the same issue with the Flanders after calibration (regardless the wrong settings I used for the calibration itself).
Do you think it could be related to the values shown in the RGB balance graph of the verification ? There is a clear green shift on the 5% value… Picture attached.
Do you think the black drift compensation option can make a difference ? Or if I increase the override minimum update display delay time ?
Thanks !!
Do you think it could be related to the values shown in the RGB balance graph of the verification ?
Doesn’t look like it (also, the RGB balance is just informational – the dE in the overview is what’s visually relevant).
Do you think the black drift compensation option can make a difference ?
Not for colorimeters (they don’t use or need sensor black calibration like spectrometers).
