Here's a photo of the setup I was talking about
:
http://www.pbase.com/gregbradley/image/115499554
It works well up to 10 minutes exposures. I was getting some eggy stars starting at 15 minute exposures so there is some flexure occuring.
I have recently acquired a Vixen VMC95L with a focal length of 1045mm
but it is very small and light and does not require a diagonal to replace the Astrotech 66ED and hopefully even better guiding. I can always find a guide star with this setup.
Greg.