Wednesday night I managed 40 minutes on the eagle nebula.
I think this time I got this offset right on my QHY8 [gain 0 offset 50] . I got the sky glow down to under 800ADU. It made a huge difference to the final. When the clouds eventually rolled in I left the scope and took about 200 min worth of darks (5x light exposure time) + 100 bias and around the same number of flats.
I'm using CCD Stack to calibrate the pictures. I managed to dark substract the subs but applying the flats afterward screwed things up real quick. Doing a pixel math and dividing by the file though held a much better result. I thought that's what it did automatically.
Need to work on this still. Anyway here's the shot with no flats applied:
http://www.multiweb.com.au/astro/M16_f.jpg
My previous attempt was at [gain 1 offset 110] and required a massive amount of processing to get rid of the noise - so the change in offset made a massive difference with the raw data:
http://www.multiweb.com.au/astro/M16.jpg
M16 is on my list of target from Wiruna along with M42 this week-end. So I should have some real crisp data to play with next week.