OAG with small refractors?

[Saturn488]

Trying to adapt a ZWO OAG to a small 60mm refractor but unsure if it will be suited or not. Are OAG's better with longer or shorter focal length telescopes?

[Craig_]

I've not used an OAG on a 60mm refractor, but I can't see why it wouldn't work. I've used them on 80, 90 and 120mm refractors with good results. IMO OAG is far, far superior to a guide scope in terms of guiding performance (at least I have gotten consistently better results with OAG) and this has been independent of aperture/focal length. Obviously OAG can sometimes have an issue of not being able to find a guide star, but I'd suggest this is not likely to be an issue on a 60mm refractor and certainly has never been on any of mine. YMMV of course.

OAG is traditionally recommended for long focal lengths, but that doesn't mean it can't or won't work with shorter FL. Indeed, I find it works much better.

[Paul Haese]

I can say I'll never go back to a guide scope with any scope over 70mm in diameter. I have used an OAG with an FSQ106 and found it easy to setup. Guiding then is devoid of differential flexure. Even a 60mm scope would work with this solution. Just watch out for the image circle. You'll need enough room to allow the prism to be in the image circle and to be out of the way of the sensor. That will not likely be possible with a large sensor. It would then be the only time you would need to use a guide scope.