I looked in Rawpedia. Perhaps I missed it but I did not find an explanation of the two tone curve menus in Rawtherapee. I can set either or both as linear, custom, parametric or control cage. A second dropdown menu has options film-like, standard, weighted standard, saturation and value blending, luminance and perceptual.
Blind trial and error seems to show some option combinations don’t do much while others make major appearance adjustments.
Both tone curves effect the appearance of the currently edited image. Do the two tone curves form a composite average somehow?
Rawpedia still needs a work. I’d be happy to help out but…I’m too much a beginner yet. I do love the software.
…what is black box? Perhaps I missed it. I saw no discussion at all about two curves (1 and 2) and how they effected each other.
That tone curve2 makes changes AFTER and on top of changes from tone curve1 wasn’t easy to find, if it’s there at all.
Searching for “tone curves” returned a “create this page” suggestion. Perhaps a lucene or plucene search mechanism would better connect keywords to pages that are already there.
No one (not many anyway) read online instructions from beginning to end, as if they were a textbook. Internet online help and tutorial is all about keywords. That’s the brave new world we live in.
…black box is a term I heard a lot when designing user interfaces. I’m retired now but it was a common term, way back when dinosaurs and Borland C++ first roamed the mid-to-late 1990s PC world. Black box is roughly synonymous with trial and error.
I have checked Exposure - RawPedia and it seems that nowhere does it mention explicitly how tone curve 1 and 2 interact. It is something we all take for granted
Subsequently, I think providing an option for changing the blend mode between the tone curves may be a worthwhile suggestion.