Rick, this is not a full frame, but close to it. I cropped it to help composition a bit. The CDK design really does offer coma free stars clear out to the edges.

Matt, Rick has some great suggestions above regarding subframe duration. I am afraid I am not as methodical in my approach. My subs for M13 were 5 minutes. I stretched the first sub to make sure that the core was not burned out. It looked pretty good, so I proceeded. I was afraid 10 minutes might have been to much, although 10 is usually what I use for deeper stuff, ie less luminous galaxies and nebulae. For Orions Nebula, I used 1 minute subs for the core, and 10 for the nebulosity and then layered the 2 togeher. As long as you haven't saturated an area, you've got something you can work with. I am not sure if this helps any, but again I think Rick offers a more repeatable and dependable method.

Andy, I am using a Paramount ME. I guess I should be more forthcoming with imaging information when I post. Sorry about that. Here is the info for this image:

Mount: Paramount ME
Scope: Planewave CDK 12.5
Camera: STL 11000
LRGB L: 7x300, R: 4x300, G: 4x300, B: 4x300
FWHM for most of imaging session was 2.4-2.7
Processed with CCDStack and Photoshop

Thanks everyone for your comments and input.
Kent