Celestron CPC8"GPS SCT astro?

[iwols]

just a querie,ive been looking at the above and wondered if they were any good for astro (Dso and planetary)work and would they accept a dslr without hitting the bottom of the fork thanks

[michael.h.f.wilkinson]

A fork mount for imaging is OK for planetary (but only OK), but not ideal for DSOs due to field rotation. An EQ wedge could sort that, but I have rarely heard of people actually liking such a configuration. I bought my C8 with a Vixen GP mount (which is a GEM in more than one way ). A proper GEM is the way to go for DSO work, although the 8" SCT is not the best for that, due to its long focal length.

[brantuk]

It depends - if you have a dual speed focuser fitted on the visual back, then add a dslr or eyepiece - the CPC800 doesn't have enough clearance when pointing at or near the zenith. But with only a dslr at prime focus then it'll be fine pointing directly upwards (just). The CPC925 on the other hand has a lot more room and can take most accessories in all orientations.

A webcam or planetary cam is a better option for imaging planets and the tracking is fine being alt/az. But for dso imaging you'll need a reducer, and the heavy duty wedge, in order to change to RA/Dec tracking - along with a ccd camera or dslr. It's a bit of a flaff each time if you're mobile - but great if the scope is fixed in an obsy and you only need to set up once.

Hth

 

[iwols]

thanks guys all explained well as usual cheers

Edited April 1, 2016 by iwols