Heres a version processed without colour stretching just dynamic stretching in Iris , and masking in photoshop
Larger version here
http://www.iceinspace.com.au/uploads...ilteredmed.jpg
This shows the background faint cloud better.
Scott
PS, Octanes method of doing flats works well too, I emulated that here, after finishing imaging I took the lens with camera still on to my PC with paintshop pro showing just white on the monitor , pointed lens at that for a flat field