Thank you for the dark frame. Thank you for the dark frame. I've averaged central part of the image using RawDigger: https://www.dropbox.com/s/ciftfhp8zgfkxfp/Screenshot%202017-03-26%2008.4... Black subtraction is off, averaged values are 2044.5, 2045.6, 2047.7, 2046.2 (rounded in red). Entire image is purple because black subtraction is turned off. Next screenshot shows black values determined by LibRaw using black frame integration: https://www.dropbox.com/s/fcxybepvflf0ec9/Screenshot%202017-03-26%2008.5... (bottom left corner): 2044, 2045, 2047, 2046 Looks like masked pixels averaging is right (may be 1 level off for G2), it is in very good agreement with black frame ('real black') data. I do not see any reason to switch from masked pixels averaging to metadata value. -- Alex Tutubalin @LibRaw LLC reply
Thank you for the dark frame.
I've averaged central part of the image using RawDigger: https://www.dropbox.com/s/ciftfhp8zgfkxfp/Screenshot%202017-03-26%2008.4...
Black subtraction is off, averaged values are 2044.5, 2045.6, 2047.7, 2046.2 (rounded in red).
Entire image is purple because black subtraction is turned off.
Next screenshot shows black values determined by LibRaw using black frame integration: https://www.dropbox.com/s/fcxybepvflf0ec9/Screenshot%202017-03-26%2008.5...
(bottom left corner): 2044, 2045, 2047, 2046
Looks like masked pixels averaging is right (may be 1 level off for G2), it is in very good agreement with black frame ('real black') data.
I do not see any reason to switch from masked pixels averaging to metadata value.