Guide scope question

[Daz1969]

Hi all, probably a stupid question but can you use a short n stubby reflector as a guide scope rather than the long reflector type ?

Cheers

Daz:iamwithstupid:

[Psychobilly]

Yes(ish)

What is the main scope that our looking to guide?

Traditionally the Focal length of the guide scope needed to be longer than that of the "imaging" scope however with modern CCD guide cams and guiding software the position of a guide star can be calculated to sub pixel resolution allowing a shorter focal length guide scope to be used... another advantage is the shorter focal length guides will probably be "faster" and have an inherently wider FOV making finding a guide star much easier...

Billy...

[philj]

I use a short an stubby reflector as a guidescope, a MAk 127, physically its short & stubby but its F12 and gives nice accurate guiding.

But as Peter says with modern ccd guide cams the FL is not really an issue these days.

Philj

[Daz1969]

Ah i see. I will be using a Celestron C8 on a Heq5 and currently have an old 60mm / 700mm refractor waiting in the wings to be used as a guide scope ,but iam realising that a good wide field of view would be a good thing.

Cheers

Daz

[Psychobilly]

Most of the time my CPC800 used to be the Guide scope for my Megrez72...which was a bit of a waste really...

So.....

I have no added a 500mm f8 telephoto lens with a DSI IIC as the guidescope allowing me to image through both the CPC800 and the Megrez72 at the same time...

Billy...