- This topic has 1 reply, 2 voices, and was last updated 1 year, 7 months ago by
.
-
Posts
-
I’m trying calibrate my LG C3 by generating a 3DLUT after profiling. While the procedure works, my results have thus far been less than stellar.
There are two major issues: First one is that the tonal response curve gets significantly worse after applying the LUT. Second problem is that I can’t get the LUT to handle out of gamut colors gracefully. Absolute colorimetric intent puts the gamut off axis and desaturates part of the gamut too much. Perceptual does a better job with the out of gamut colors, but more of the in gamut colors are off.
Here’s an example of absolute colorimetric intent:
As you can see there’s a slight tilt off axis of the entire gamut and around the top of the triangle there’s some serious desaturation going on.
Diff. EOTF doesn’t look pretty either. Granted, the errors are small but looked much better before applying the LUT, with simple manual calibration.
And this shows serious issues with clipping:
None of these issues occur with default settings or manual calibration.
Question is: What is the proper procedure to create a good high quality LUT?
I have used the very large testchart for LUT creation, with added neutral patches and iterative patches (5072 patches in total).
I have tried setting the display to both full and legal levels.
3DLUT Maker settings:
As mentioned, I have tried with different rendering intents. I have also tried different input/output encodings as well as setting tone curve to unmodified (which, strangely enough, seems to modify the tone curve).
I would very much appreciate some help here. Perhaps I should also mention that the calibration will be strictly for PC use, where I’m targeting rec 709 gamma 2.4 for color grading.
If you had issues with aWOLED due to its W pixel behavior and RGB clipping when getting certain brightness… it’s likely that you may get an answer on ArgyllCMS mailiist for that specific case. I do not own an WOLED hence I’ve not tested the irregular behavior of those displays.
DisplayCAL is calling ArgyllCMS “collink” application to generate LUT3D:
https://www.argyllcms.com/doc/collink.html
hence if there is any specific parameter that may help you, ask in ArgyllCMS maillist. This way even if such parameter /config was not supported by DIsplaYCAl you can run it command like from your custom XYZLUT profile.
