Hi there, first time posting both here and in the darktable github repository.
I spent some time getting familiar with the darktable source code this Christmas and ended up with something actually interesting and figured I might as well share it with the rest of the community.
It’s a tone mapping / look transform / scene to display conversion (or whatever you want to call it) that is based on a sigmoid function instead of a cubic spline like the base curve. I’m not 100% how the filmic module is implemented so I will leave the exact comparison to that out for now. The purpose is the same though.
THIS IS ONLY A TEST BY ME SO FAR. Not endorsed by any other developers yet.
Head over to [WIP] sigmoid tone mapping module by jandren · Pull Request #7820 · darktable-org/darktable · GitHub
if you want to try it out (assuming you know how to compile), read more details or see comparative examples.
I will leave this post simple with some results. All have large exposure corrections and some white balance applied. The rest is specified under. Please add your results if you try the branch!
log-logistic, contrast = 1.4
log-logistic, contrast = 1.67
And that is me if anyone wonders.
weibull, contrast = 1.47
And some pictures from the forum as that gives you the opportunity to compare against other edits:
A study in blue
log-logistic, contrast = 0.89
Landscape by phweyland
tone equalizer, strong preset, log-logistic, contrast = 1.95
Lightning with long exposure
log-logistic, contrast = 3.07