With some photographs in need of heavy brightness editing (e.g. heavy burning/dodging and curves, e.g. underexposed photos), what is the best colour model to edit in? Editing in plain RGB often makes huge hue shifts, which make it ugly especially if the edit is local only. Editing in L from LAB mode leaves all colours severely desaturated upon "exposure" boost (but keeps the hue, unlike RGB), requiring a Saturation boost afterwards (but it's hard to tell how much will be needed, to bring it back to normal). I guess it's because of nonlinear gamma that the RGB photos make hue changes upon changing brightness. How about reversing the gamma curve to linear (when one knows the exact curve), brightening and applying gamma again? What I also tried is editing in HSB and HSL spaces. These preserve hue and saturation upon editing of B/L (unlike LAB space), with the best so far seemingly the HSB space, where the channels do not clip as with RGB heavy levels/curves change, nor are there any colour shifts as with RGB. I can recommend it, but I don't know if it's suitable for all photographs - I know very little about these colour modes, what do others thing about editing in them? Could there be some problems? And if it is so much better to change tonality in HSB, why the heck Adobe hasn't yet implemented it directly?
Thanks for comments,suggestions,et cetera. Are there some Curves/... plugins that make editing in other than RGB easier? Now it's a bit tedious - the Adobe plugin "HSB/HSL" is quite awkward to use. Frantisek
