More > JRiver Media Center 31 for Windows
JRVR > Calibration > 3DLUT Gamma (tone curve) - what is it?
mattkhan:
as per subject, how exactly is this used in jrvr/libplacebo?
reason to ask is it seems like a lut produced from the same measurements (in cube for jrvr vs madvr formats) produces visibly different levels coming out of black (white looks normal) in that it is coming out of black much faster on jrvr. It makes me think I have this configured incorrectly.
Hendrik:
The 3DLUT has to be generated with a certain (input) gamma curve, you have to tell JRVR which one that is, so it can properly prepare the data for it.
mattkhan:
ok thanks
as far as I can see, displaycal has no explicit option for this, just the source colourspace (so rec709 or dci-p3 d65). I think that means 2.2 is the right setting but hard to be 100% certain about that. Having said that, not setting it to 2.2 is clearly off visually so I'm pretty sure 2.2 is the way to go
mattkhan:
measuring in my room at this time of day/year is not perfect but measuring "the same" 3dlut (i.e. generated from same displaycal settings & measurements except the output format) and then measuring in room back to back & there's quite a difference (that is repeatable if I do this n times)
I'll measure again later in the week when it's properly dark (which should fix up the low end, my room has a tiny bit of light bleeding in during daytime which affects the very bottom end) to be sure but there's a difference here that is surprising and I think reflects what I'm seeing visually.
mattkhan:
I measured without lut disabled in both cases for comparison, the differences are quite large again
options for where the problem lies
1) how jrvr applies the LUT
2) how I've created the LUT
3) how I've configured jrvr
any ideas on how to work out where the problem(s) lie?
Navigation
[0] Message Index
[#] Next page
Go to full version