Thanks Leon. Did you notice the Pencil Neb is S shaped. The other thing I have found is that using a 1250mm Mak to guide a 300mm lens really shows how good the lens is. The mount has been drift aligned with the SN10. If you don't believe me zoom in! After a nights exposures the first frame was only a few pixels different from the last.
I can do up to 32 minute exposures with NB at 800ISO at f/2.8 without blowing out or running out of dynamic range. The fridge is the best thing I ever implemented. These images are impossible in summer with a DSLR with an ambient of above 5C.