GM-8 vs GPDX

I know this is an old discussion, but would like some quick info. Equip I have: GP on wooden tripod, 9.25, ED80, Canon 20D. Purpose: I would like to dabble in astro photography and right now I'm considering GPDX with SS2K. Thanks

I sometimes saw vibration on the GM-8 at high
powers (like 400x) during visual use on double
stars and planets with a 4" and 5" F9 refractor,
but this would not affect imaging. This was
using the Digital Drive System with the stepper
motors; I expect Gemini upgrade which has servo
motors would be smoother (though $$).

At some point you might want to auto-guide. Auto-
guiders are getting cheap and easy to use. The
GM-8 will have an input socket on the controller
where you can connect the auto-guider. But I'm not
sure about the GPDX; you might check on that.

Probably for just getting started in photography,
either would be fine. You just might hit different
limitations in the future.

I can't comment on the GM-8 or GPDX, as I have a Vixen Sphinx, but perhaps you could check the yahoo forums specific to each mount for more information.

Gerald

I suspect both the GM-8 and GPDX will be slightly overloaded, for photography, with the load you describe. Disturbances will cause vibrations that don't settle quickly. So it will be more challenging to get sharp photos.

I have a GM-8, C9.25, Nikon D80, and an off-axis guider. The GM-8 is slightly jittery in this configuration, for photography. Of course, this load includes counterweights for both RA and DEC, and some accessories. It still works, its still fun. Its just more sensitive than with a lighter scope.


--sf