I am having the problem that my compact camera (Sony RX100) has a very, very odd and strong form of vignetting. If I correct this with flats or the gradient removal tool, some rather odd rainbow colors are introduced instead. Please see attached pictures with vignette and after flat/gradient removal in Siril:
I was wondering what model Siril uses to correlate a desired change in brightness to adapt the individual RGB channels. Imho, to half the brightness of a pixel to correct the vignette, one should not just reduce each RGB value by 1/2.
See also this discussion: image - Formula to determine perceived brightness of RGB color - Stack Overflow
How is this handled in Siril and is there a difference between working with bayered and debayered data?