"I don't want to use an OAG!!"
Then you are setting yourself up for endless struggles and repeated failures trying to use "piggy back", which is only useful for short FL.?
So one approach?would be?to use Hyperstar, which?converts the scope to?a very short FL and thus demands little of the mount and guiding and also allows for short sub-exps due to the high pixel flux.? But this produces low resolution images that are basically equal to a small refractor, though?requiring much less time.?
If you desire high resolution then image at prime focus via:
1) OAG with AO (e.g. SBIG)
and/or
2)?well tuned and aligned, high quality?(expensive) mount?such as?AP or Bisque and a very low noise camera (<5e-).?That combination?allows short sub-exps at prime?with?minimal?guiding.
or
3) high speed imaging?via EMCCD or ICCD. This is expensive?and?there are?no turn-key packages for astro (i.e. it is a lot of work to get started).
Stan
