Work in Progress - 3dLUT support

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Post: #226
Sorry, what I wrote was misleading. I had calibrated the projectors color and gamma using HCFR and the results were visibly neutral. Now profiling it with displaycal and vcgt "on" gives reddish pictures, whatever I do. Without the vcgt option I hardly see any difference.

Somehow the authors of displaycal explains things similar but then again very different. See here: https://hub.displaycal.net/forums/topic/...#post-6794

Could someon please point out how exactly the correction-process is working? A part in the grafics-cards LUT and another part on top of that in kodi (or madvor or whatever)?
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Soli Online
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Post: #227
He basically says the same.
If you already have calibrated grayscale on your projector and the result is good, then you can turn off VCGT. It can be enabled but it might be hard to better a manual grayscale in the context of measuring reflection from a projector screen, unless you have reference meters.
I'm not sure if it's possible with HCFR but in Calman you can profile your meter to the same meter. Which means you can use a measurement from you projection screen as the reference and offset it to a reading of the lens directly (remember to put diffusor on). Voila no more problem with sensitivity. You'd do similar if you were to calibrate a 3D mode of a TV.

If you want, then you could always post a measurement of Colorchecker SG, and saturation sweeps at 25/50/75/100 stimilus, and I'll let you know what I think.
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Post: #228
Ok, thanks for the info. That makes things clearer. So the whitepoint and gamma are quite up to spex due to my manual measurement and the color mixing part of the X3 is simply already pretty good, so I see hardly any difference when turning on the 3dLUT in kodi.Still wondering why I get such a red tint when using vcgt. From what I understand the vcgt should simply be linear when gamma and whitepoint are ok. When I find some time I will look into it again.

Colorchecker SG is the board I can buy for 300 €?
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Soli Online
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Post: #229
No it's built in HCFR, but yes It's based on that board. it's the same patches that are measured and gives you a good view of the color accuracy and
That said, A full Colorchecker SG might be overkill. The "Calman Classic" preset should do fine.

Measures/grayscale and colors
Measures/saturation/colorchecker

Look at CIE diagram, it should give you an idea how accurate your colors are while gamma graph show you the gamma (obviously). Rightclick graphs to remove unneeded details and save at, say, 1500x1000 pixels.

Then change Colorchecker presets to "CM 5-point Saturation 75AMP.and do a new Colorchecker measurement, then save this as well.

These 3 graphs will give you a good impression of how accurate the manual calibration is, and you get a clear picture of how much better it can be with a 3DLUT depending of how close you hit the targets in the gamut.

Remember to use GPU FULL in Windows, but make sure HCFR is using 16-235 (measures/generator/configure/GDI Options + make sure disabled video lut is checked as well), and that projector is 16-235/limited range as well.

Of course you saying that you've already used HCFR would imply that you know all of this already, but from your answers I'm not so sure what exactly you know and don't know, so sorry if any of this seems obvious.
(This post was last modified: 2017-05-04 15:10 by Soli.)
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Post: #230
Thx for the detailed "howto". The basic setup (levels and so on..) I knew, how to check for the accuracy I didn't, so every hint is very welcome. Smile

I will check it out, it might take a couple of days, though. I need time and it has to be at night...
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