I've recently discovered CosmeticCorrection tool removes hot pixels
much better from non-debayered CFA images rather than from debayered RBGs. So I switched
Raw format preferences from the default
de-Bayer RGB to
Pure Raw and tried make my master bias/dark/flat frames and calibrate my lights in non-debayered form, and debayer them after calibration. It looks like it works OK, but I found one strange thing I can't explain.
If I open single
bias frame (1/4000) and single
dark frame (5 min) with
de-Bayer RGB option the images statistics are consistent with a theory: mean value of the dark frame is about twice as high as mean of the bias frame, and standard deviation of the dark is about three times higher than standard deviation of the bias.
However, if I open
the same files with
Pure Raw option, the mean value of the bias and the dark frames are almost the same! The only difference is standard deviation. By definition, raw dark frame contains both the bias pedestal and the dark current, while raw bias frame contains only the bias pedestal. How on Earth they can be the same? Any ideas on what's going on?
