So this is the first image where I have had the ASi1600MM on my old 10" f5 imaging newt. I have been playing around with the camera on shorter focal length scopes (<1000mm). I was abit concerned about it at the 1250mm fl of the newt but not that bad.
The image consists of 25 x 60sec subs for each filter (RGB&L). Processed in DSS with Darks and Bias but no flats. Photoshop CC used for layering and colourising etc. Luminance was used as soft light and dialed the opacity back.
BTW, yeah I forgot to put the coma corrector on, I have been using the camera on the Mak-Newt and the refractor, so tend to forget about it.
Astrobin files are here: This one with notes,
http://www.astrobin.com/253988/
Full Screen here:
http://www.astrobin.com/full/253988/0/
I know it's not perfect, but one of my first RGB images with a mono camera.
Thumbnail quality below is pretty bad, look at the Astrobin ones.