[alpal]

I have an interesting photo - below -to show for this thread.
You can see the difference in the graphs between
on the left - low speed readout for my QHY9 mono &
on the right -high speed readout.

At -30 degrees DARK FRAMES:
The low speed is giving a median noise of about 1025
& the high speed median of about 4200
out of a maximum of 65536.

4200 is just at the area of sky noise so obviously
the low speed readout is essential.
The high speed readout should only be used for quick captures to see the target but never for real data.
Unfortunately I did not know this & all of my pictures have been taken
with the high speed readout.
If only I would have read the manual more closely -
I would not have made this mistake.
Really - the QHY9 capture program called EZYCap should not allow you the option
of high speed for capture - except only in preview or focus mode.
I expect my pictures in the future to be a lot better knowing this
& also the fact that I have upgraded from an 8" f6 to a 10" f4 Newt. -
the difference should be huge.

cheers
Allan