Since darktable introduced the scene referred workflow I would argue it's an extremely steep learning curve for anyone coming from display referred software (Lightroom, Capture One etc). Scene referred is very much a cine-thing and I know of no other still image software that uses it. dt v3.6 made scene referred default. Aurélien has been one of the driving forces behind the switch to scene referred and his hour long…
For anyone caring just enough to wonder what scene referred and display referred are talking about… scene referred does its filtering and mapping work on the pixel values in a linear space, presumably linear to "photons observed" but I could be wrong there. display referred does its filtering and mapping on pixel values which have already been through a nonlinear function to make them appropriate for display. The sce…
You are correct. If you see Y light in real life, and that corresponds to a pixel value of 1000, 2Y light should correspond to 2000.
> display referred does its filtering and mapping on pixel values which have already been through a nonlinear function to make them appropriate for display.
The nonlinear function is usually 0 brightness to 100% brightness of the media (for instance, pure white on a printed piece of paper or pure white on a display). Scene referred photos technically have no bound (there is clipping, but you can just expose less and increase the exposure in editing to effectively get the same thing)
Of note is that you have to change a scene referred color space into display referred color space anyways...