Regarding the statistics and rejection of them: The outlier rejection works a little bit differently.
Yes of course, but i will not do the calculation for the 65 frame stack by hand. The statistics for all the frames do not differ much from this “back of the envelope calculation”. The APP statistics for this master dark show a standard deviation of 125, close to the 112 that you see in one frame. (yes, that is sdev for all pixels in one frame versus one pixel in all frames so not correct either….)
FITS HDUs: 1
HDU1 – SIMPLE = T / Java FITS: Sat Apr 29 11:01:14 BST 2017
HDU1 – BITPIX = 16 / bits per data value
HDU1 – NAXIS = 2 / number of axes
HDU1 – NAXIS1 = 4520 / size of the n’th axis
HDU1 – NAXIS2 = 3616 / size of the n’th axis
HDU1 – EXTEND = T / Extensions are permitted
HDU1 – BSCALE = 1.0 / scaling to 16bit
HDU1 – BZERO = 32768.0 / offset data range to that of unsigned short
HDU1 – DATE = ‘2017-04-29T10:08:46’ / creation date of master dark
HDU1 – SOFTWARE= ‘ Astro Pixel Processor by Aries Productions’ / software
HDU1 – CALFRAME= ‘master dark’ / master dark frame
HDU1 – INSTRUME= ‘QHYCCD-Cameras-Capture’ / instrument name
HDU1 – CFAIMAGE= ‘no ‘ / Color Filter Array pattern
HDU1 – GAIN = 1.0 / gain or ISO depending on instrument
HDU1 – EXPTIME = 600.0 / exposure time (s)
HDU1 – MEAN = ‘ 7.79E+02’ / mean of channel
HDU1 – MED = ‘ 7.75E+02’ / median of channel
HDU1 – SIGMA = ‘ 1.25E+02’ / standard deviation of channel
HDU1 – NOISE = ‘ 2.50E+00’ / MRS gaussian noise estimate of channel