Thanks everyone!
(i've now had a whopping 45 minutes of sleep so feel all refreshed...
)
Thansk Jim, Bill, Ric and John.
Jim, Thanks for tweaking it up! I struggled a bit with this one in terms of black point settting. I only imaged after the moon had set so i didnt have to worry about skyglow from the moon (i've now done that two nights in a row and I'm beat!). I looked long and hard at the pattern of faint red nebulosity to see if it was indeed sky glow or vignetting but in the end because of the pattern i thought that probably the 20Da with it's sensitivity for red spectrum had probably picked up some nebulosity so i left it in.
I like the contrast of your reprocessed one better though. i think what i should probably do next time (when I have tracking i can trust) is go for more exposures including longer ones to really build up the faint stuff and thus enable a clearer contrast or show it up for being skyglow and remove it using the good old Gaussian blur trick. Until then i think your reprocessed version is better, thanks.
cheers
frank