Question Is multistar guiding with a guidescope preferable to an OAG for M-Uno/M-Zero?

Hi all,

I'm wondering if multistar guiding with a guidescope is preferable to an OAG (assuming multistar is not possible with the OAG) now with the Avalon M-Uno and M-Zero fast reverse mounts. Obviously, you want the shortest viable guide exposure when using these mounts so it is important to control the seeing. I'm going to go back to trying an OAG soon but I wonder if I will be better off with something like a 200mm guidescope so I can benefit from multistar guiding.

So what do you think, is a guidescope preferable to an OAG now that we have multistar guiding?

Danielh21,
I started using a 240 mm guide scope on my Celestron C11 SCT (on an M-Uno mount) fairly recently. I had been using an OTA previously). So far I have only had a couple of nights to use it as the weather has been pretty cloudy of late, but it is showing much promise over the OTA. I am using an ZWO ASIAIR Pro for the multi-star guiding and the two times I have been able to use it the guiding was pretty good. I am still tweaking things to see what the best setting are. I will provide an update when I have had more time to use it.
Vince C.

Hi Vince,

Thanks for your response. I look forward to hearing more of your observations. As luck would have it, I actually just figured out that my Esprit 100's field flattener is essentially incompatible with the ZWO OAG because the prism stalk interferes with the threads. So I may actually have to sell the OAG already and buy a decent guidescope.

Were you using the guide scope on the dual-dec adapter or mounted on the OTA itself?

Dan

Hi,
I am using the Avalon Linear, but the mechanics should be the same, so it shouldn't matter.

I always use an oag (zwo oag + 290mm mini) with my 3 telescopes: TS optics triplet @ 380mm, esprit 120ed @ 840mm and EdgeHD 8 @ 1495mm. I never had an issue with using OAG + multistar guiding, except with the EdgeHD. In some areas of the sky, I hardly had 1-2 stars anyway in the oag's field of view.

I use 1s as exposure time in PHD2, and rarely bump it to 1.5-2 seconds if seeings is really bad

I have the guide scope mounted on the OTA.

Michel wrote: Hi,
I am using the Avalon Linear, but the mechanics should be the same, so it shouldn't matter.

I always use an oag (zwo oag + 290mm mini) with my 3 telescopes: TS optics triplet @ 380mm, esprit 120ed @ 840mm and EdgeHD 8 @ 1495mm. I never had an issue with using OAG + multistar guiding, except with the EdgeHD. In some areas of the sky, I hardly had 1-2 stars anyway in the oag's field of view.

I use 1s as exposure time in PHD2, and rarely bump it to 1.5-2 seconds if seeings is really bad

Hi Michel - did you do anything to make the OAG fit the Esprit? As I mentioned before the field flattener protrudes too far into the threads on the OAG and collides with the prism stalk. People on CloudyNights said they had to grind down the threads on the flattener.