Which guidescope to buy ....

[John Gill]

Hi,

I am currently running a Celestron 8"EdgeHD on an AVX mount.  So I need to buy a guide scope and an Autoguide camera.

My telescope guy recommends a Celestron 80mm guidescope and an Orion Starshooter with PHD.  So question time ....

Is this a decent guidescope and is it possible to connect my camera to the Celestron 80mm scope with a wide field of view and then use the 8"Edge HD as the guidescope?

Regards

John

[libraryman]

No expert for sure but your edge will be pushing it as a guide scope I think....better to get a small finder scope for guiding the 80mm, cheap as chips and a good match in pixel scale .

The 80mm would be o.k I guess as a guide scope for the Edge, but guiding at long f/lengths can be difficult though not impossible.

Ray

[spaceman_spiff]

Hi there,

The 80mm scope will make a great guidescope. I have had excellent results using the similar SW ST80. As for using the 8 inch as a guide scope, I think that the 2000mm focal length will make you guiding very sensitive to small vibrations and wind-induced movements (one small nudge and the guide star will fly out of the FoV).

You cloud give it a try but don't be surprised if it becomes very difficult.   

[Floater]

You cloud give it a try but don't be surprised if it becomes very difficult.   

Definitely something Freudian going on here.

[rl]

Are we talking about the 80mm f/5 or the 80mm f/11?

The former is very popular because it is cheap and compact, and ok mechanically. They're something of an institution as autoguiders

The long one will do an excellent job guiding a long fl scope but the choice of guide stars will be more limited

As said above, if you turn then around using the edgeHD to guide, in theory the guiding should be perfect but mirror flop or some other mechanical could completely throw the guider.  Conventional wisdom says your ST80 will have field curvature issues and purple haloes on the final image.  Try it and see...an experiment al result is worth a dozen posts! You might be very happy with the result

RL

[John Gill]

Thanks for the info guys.  Perhaps a better question would be "What is a better guide scope that could double as a imaging scope as well?"

[spaceman_spiff]

Definitely something Freudian going on here.

Ha ha!

I didn't even notice that...I have a Freudian autocorrect!

[spaceman_spiff]

Thanks for the info guys.  Perhaps a better question would be "What is a better guide scope that could double as a imaging scope as well?"

Skywatcher ED80?

[Tinker1947]

Thanks for the info guys.  Perhaps a better question would be "What is a better guide scope that could double as a imaging scope as well?"

One of these would take a good image....

http://www.firstlightoptics.com/william-optics/william-optics-gt-81-triplet-refractor.html