Guide scope - ST80 or finder/guider?

[animaal]

Hi,

I'm looking to put a guide scope on an Altair 80 Apo. The two obvious options are either (a) the Altair 10x60 finder/guider, or (b ) an ST80 mounted piggy-back.

I'm tending towards the Altair 10x60, for the following reasons:

1. Less possability of flexure (or so I've read)
2. With the short focal length of the main OTA, the focal length of the either guider won't matter
3. If I get a long focal length OTA in the future (e.g. C8, focal length 2000mm), neither option will suffice anyway - I'll probably need an OAG.
4. Easier breakdown and setup with the finder/guider
5. Finder/Guider is possibly a better finder scope - wider field of view?

On the down side, the ST80 would be cheaper, and would double as a second OTA.

Is there anything I'm missing? Does the ST80 option deserve more consideration?

Thanks.

[Davey-T]

I've used the ST80 as a guide scope on a 110 f/7 refractor, a 10"SCT 2500 F/L and also as a handy little  solar scope so more versatile than a finder guider and easy to resell if the need arises.

Dave

[Thalestris24]

Hi

I expect the finder guider would do. I've used one with a 130pds and with a 150pds. However, I just ordered one of these. I figured it was worth a punt for a mere £39 It looks like the ST80's little bro

Louise

[orley]

I've used a 9x50 finder for guiding for over a year now, not a single issue with it. Nice tight stars in my images.

[animaal]

Thanks for all the comments. It sounds like either will work fine with an 80mm refractor. I'm surprised to hear that the ST80 would work well at focal lengths of 2500mm. That makes it more tempting. I've only ever used a Telrad as a finder, so I could use a smaller RDF alongside the ST80 and not worry about a dedicated finder.

[Davey-T]

Thanks for all the comments. It sounds like either will work fine with an 80mm refractor. I'm surprised to hear that the ST80 would work well at focal lengths of 2500mm. That makes it more tempting. I've only ever used a Telrad as a finder, so I could use a smaller RDF alongside the ST80 and not worry about a dedicated finder.

According to the "experts" modern sub pixel guiding means that most combo's work.

Dave

[fondofchips]

Here's my ST80 finder mounted on a SW 200P, well worth the effort, I bought adjustable mounting rings to help with alignment.  It is mounted on aluminium channel bought from the local metal merchants.  Note that some bolts are 6mm thread and others the standard 1/4" thread found on tripod mounts, I bought the 1/4" bolts I needed from Ebay. 

Cheers,

Fondofchips.

[animaal]

Thanks again, that's all really useful information.

It looks like I may be as well off to go for the ST80 for guiding, and maybe eventually a separate RDF for finding.

It's not as neat as a finder/guider, but maybe more flexible in the long run.