Quote:
Originally Posted by ChrisV
I got these values on an 8" F5 newt with the ASI071 at unity gain (90) and offset of 20 running at -5C.
I've gone through a few images and the better ones (with darker backgrounds) have a background sky value of about 1300 for 6min subs. I think I worked it our properly - opened the fits file in fitswork and read off the minimum value on the histogram.
At this gain/offset - the offset/bias frame had a mean value of ~80 ADU (+/- 10).
|
thanks that is great. At gain 90, the expected ADU is 290, so you could get down to that by reducing the exposures by a factor of 4 (to ~1.5 minutes) if you wanted, without doing any damage to the SNR. That would give better dynamic range and possibly better resolution.
sorry to be a pest, but what is your Bortle scale sky brightness?
https://en.wikipedia.org/wiki/Bortle_scale.
thanks again cheers Ray