This is the first image where I knew what the sensor temperature was through the whole collection procedure. That is flats. darks for flats, darks and finally lights. What better object to look for noise than the Coal Sack.
Full res image Warning 15MB
http://d1355990.i49.quadrahosting.co..._04/coalsL.jpg
The usual HDR method and no Gradient exterminator.
Bert