Camera-specific hot pixels
On my camera I get some hot pixels at longer exposure times, the higher the ISO the more. Using the "hot pixels" filter in darktable does not really give convincing results; sometimes playing with the filter parameters helps, but often I end up removing hot pixels by hand.
Therefore I would like to propose a different method to detect hot pixels: the user takes at least two photos at the longest possible exposure, one with the lens cap on to obtain a complete dark photo and one against a light source to obtain a complete white photo. On the dark photo will be some white pixels and vice versa. darktable could use these photos to locate the hot pixels and remove them. Possible improvements could be to provide one pair of photos for each ISO level and to add a switch which allows the application of the hot pixel filter automatically upon import of photos from the given camera.
#5 Updated by Christoph Schmidt over 3 years ago
Attached is a photo which was taken with the lens cap on to see the hot pixels. To my knowledge the D5200 stores raw images only as compressed 14 bit.
But please let me emphasize that I'm not looking for a solution to the problem with my particular camera but I'd like to propose a different way of how to detect hot pixels, completely independent from my camera.
#6 Updated by Christoph Schmidt over 3 years ago
It seems the file upload is not working. You can find the photo here: