[Apologize if you receive multiple copies, I tried posting via web interface first but apparently something went wrong]
Hi! I wonder whether the following is a bug or a feature. If you do mouse scrolling on the histogram then 1. on the left part (black point) scrolling will increase/decrease value of "black" slider from the exposure module by 0.001, the same effect as scrolling on the corresponding slider in the exposure module; 2. on the right part (exposure) scrolling will increase/decrease value of "exposure" slider from the exposure module by 0.15 (if you start from exposure 0.0), but scrolling on the corresponding slider always increases/decreases exposure value by 0.02(!). I think that it is a problem: scrolling on the histogram doesn't allow exposure fine tuning: in case of underexposed pictures user can't set precise exposure via histogram (e.g., for image with exposure 1.0 _one_ scroll movement on the histogram changes exposure to 1.32 that is 16x less precise than one scroll on the corresponding slider!). As I understand scrolling on the right part of the histogram invokes dt_dev_exposure_set_white(darktable.develop, cw + 0.1); (libs/histogram.c) And this value (white = cw + 0.1) is translated to exposure in iop/exposure.c: float exposure = white2exposure(white); where #define white2exposure(x) -dt_log2f(fmaxf(0.001, x)) I think that it should be fixed by changing the code in libs/histogram.c such that scrolling on the right part of the histogram will change the exposure value by the same amount as scrolling on the corresponding slider in the exposure module, i.e. 0.02. Am I right? Best regards, Alexander -- Alexander V. Smal St. Petersburg Department of Steklov Mathematical Institute 27 Fontanka, St. Petersburg, 191023, Russia ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to [email protected]
