After Xmas I did some comparing of Sigmoid and FilmicRGB with synthetic images and my checkr24 PNG file from the other topic in this forum: synthetic-image-for-understanding-darktable-modules
Both modules have strong benefits and I cannot yet judge, what will be my preference.
But i found, that FilmicRGB does less color change than Sigmoid for the checkr24 test file. The change is only minimal, but is visible and measurable for some colors when using Sigmoid. Filmic keeps the colors practically unchanged. Probably for real world photos, this difference is not really relevant. Or for special tones like skin? I need to investigate …
I feel validated that even Boris is using from time to time synthetic images to check and explain DT modules. Last week for example on http://youtu.be/yRhUEWvOW6g with “DT Episode62: Hue shift in highlights”. Thanks!