Tips on setting up an Off Axis Guider (OAG) - Forums

Topic starter

Mar 2, 2022

Here is a guide with some tips on setting up an Off Axis Guider (OAG). I find these significantly improve of your tracking and image quality.
I hope this is helpful as I feel some beginners may be a bit intimated by a OAG. Link:https://astrogeartoday.com/improve-your-images-with-an-off-axis-guider-oag-steps-to-get-started/

kuechlew

Mar 2, 2022

Thank you for the interesting and good introduction. Maybe it's worth noting that some OAGs have specific requirements towards the guide camera. E.g. if I'm not mistaken the QHY OAG requires the cylindric type of camera like the ZWO 120 which you can stick deep into the OAG. So if you already own a guide camera you may want to check first wether it fits to the OAG before you buy one.

Clear skies
Wolfgang

Helpful Concise

Rouz Astro

Topic starter

Mar 2, 2022

Thank you for the interesting and good introduction. Maybe it's worth noting that some OAGs have specific requirements towards the guide camera. E.g. if I'm not mistaken the QHY OAG requires the cylindric type of camera like the ZWO 120 which you can stick deep into the OAG. So if you already own a guide camera you may want to check first wether it fits to the OAG before you buy one.

Clear skies
Wolfgang

Good point Wolfgang and I'm glad you liked it.

I will post another short article on a few types and brand of OAGs.

Thanks,

Rouz

Christian Großmann

Mar 3, 2022 · Edited: Mar 3, 2022

Hi @Rouzbeh

I am really struggling with the setup of my OAG. I got trapped by the fact that Wolfgang ( @kuechlew ) mentioned. I own a ZWO OAG (the larger one) and tried to use it on my RC8 or my 8" Newton. Soon I realized, that I just can't reach focus. I need some more room for that. So I am rethinking my ring-wheel-flattener-etc combination to get more focus range for my guide camera. While other parts of the equipment worked nearly out of the box, the OAG is hard to install for me.

On the other hand, the effects you show in your article are well known to me and I understood, that the OAG is the solution for my kind of problem with the slight tracking errors visible in my frames. But it is the frustration that made me struggle to try it a tenth time. There is always another ring or adapter I have to buy to use the equipment I already had paid a lot for.

So my advice for everyone here is, to prepare in advance and try to figure out, if your coice of equipment will work together. I think it is worth to contact the forum and ask about some opinions. This may have helped me so much...

Anyway, I have to get the OAG running properly. I am sure, this is a must and will improve the image quality a lot. But sometimes it's hard to motivate myself

CS

Christian

Scott Badger

Mar 3, 2022

Hi @Christian Großmann

FWIW, on my C9.25 I had to use the extender that came with the OAG (ZWO - small) to reach BF for the guide camera. I think adding the helical focuser also provides more length to work with.

Cheers,
Scott

Tom Boyd

Mar 3, 2022

Really nice summary. Thank you…

Rouz Astro

Topic starter

Mar 3, 2022

Christian Großmann:
Hi @Rouzbeh

I am really struggling with the setup of my OAG. I got trapped by the fact that Wolfgang ( @kuechlew ) mentioned. I own a ZWO OAG (the larger one) and tried to use it on my RC8 or my 8" Newton. Soon I realized, that I just can't reach focus. I need some more room for that. So I am rethinking my ring-wheel-flattener-etc combination to get more focus range for my guide camera. While other parts of the equipment worked nearly out of the box, the OAG is hard to install for me.

On the other hand, the effects you show in your article are well known to me and I understood, that the OAG is the solution for my kind of problem with the slight tracking errors visible in my frames. But it is the frustration that made me struggle to try it a tenth time. There is always another ring or adapter I have to buy to use the equipment I already had paid a lot for.

So my advice for everyone here is, to prepare in advance and try to figure out, if your coice of equipment will work together. I think it is worth to contact the forum and ask about some opinions. This may have helped me so much...

Anyway, I have to get the OAG running properly. I am sure, this is a must and will improve the image quality a lot. But sometimes it's hard to motivate myself

CS

Christian

Hi Christian,

The two main points are:

1- do you have enough back focus to add the OAG after your corrector?

2 - Is the distance from the OAG glass prism the same to your main imager and your guide camera?

Usually youll need to get your guide camera as deep as possible into the OAG.

I hope you work it out, the guiding will be more accurate than a small guidescope.

Rouz

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Rouz Astro

Topic starter

Mar 3, 2022

Tom Boyd:
Really nice summary. Thank you...

Thank you for the positive feedback.

Dieter Wiedenhofer

Mar 3, 2022

Hi,
I followed this video to set up my OAG. It was really helpful to avoid mistakes. My problem was that I could not go deep enough with the guiding camera (ASI120mm mini) so I had to adjust the OAG as described in this video. No it works perfectly.

https://www.youtube.com/watch?v=3PcSljeVNLM

Hope this helps.

Best regards from Germany

Dieter

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