What are peoples opinions on OAG's V Guide Scopes

[Martyn A E]

I'm trying to put together an imaging train on a new Orion Optics CT10 and have the main camera but now am researching options for the guiding package. I am leaning towards an OAG for the reason of easier disassembly and storage of the scope off the mount.

Speaking to John and OO he said 'The CT10 setup can be alter the back focal distance without changing the secondary mirror by roughly +-20mm. At the moment they are set around 45mm from the top of the focuser'

What if any additional kit might I need for an OAG considering the above. Ive been looking at the ZWO OAG Mk2? 

 

[Realtimedoctor]

Hi, 

In my minimal experience, guidescope are easier to work with. OAG are great if imaging at FL 1000mm or more, in your case I think this stands true. Having said that, I've been using my finderscope on my 200p, as a guidescope. 

I consistently get RMS of less than 0.5. As long as your guidescope is fixed using good tube rings, there shouldn't be much difference. 

Off axis guider are certainly better, but by his much. I'm not sure. If you use OAG, the headache of backfocus, etc is too much. If you are just starting, if suggest sticking with a guidescope. If you are an experienced imager and know the in's and out's of your imaging train, go for an OAG. 

Cheers, 

Nish 

[skybadger]

I'm not sure there is much of a problem introduced by 9mm of oag. Rotator and tilter are more my problem. Oags can suffer from lack of stars at long focal lengths while you can move the guider and they have bigger fields but they do suffer from flexure. 

Edited February 12, 2022 by skybadger
Meaning

[Sp@ce_d]

I’ve not imaged with a newt but I’d be looking at an OAG if there’s enough space. Minimise any risk of flex if you can. You don’t mention if you’re using a mono with filter wheel or a OSC camera as to how much gear you need to fit in the train. The key with an OAG is to use a guide cam with a decent sensitivity. I use a lodestar & never had an issue apart from one target, M51. That was with a 8” RC. It needed manually selecting sometimes. Apart from that my current rig with the 150 frac runs on auto with ACP & is set for multi star guiding at over a metre & always enough stars.