About this product
Part Number: ZWO-OAG
New! ZWO off-axis guider (OAG) for astrophotography.
- Lightweight and only 16.5mm thick!
- Large prism - 8x8mm
- Guide through your main imaging scope - no guide scope required!
- Multiple adapters available including T2, M42 and M48 making it easy to fit to most cameras and telescopes
- Fully compatible with all ZWO ASI cameras
- Good stability - strong, stiff connection to the telescope
1. Calculate the correct distance for your imaging train. For example, you need to attach a 21mm extension to the ASI071 to reach 55mm back focus (17.5mm + 21mm + 16.5mm = 55mm).
2. Take off the guider prism part from the OAG and attach the OAG body to the telescope.
3. Insert the prism back into the OAG body.
4. Mount the guide camera.
5. Screw the T2 or M48 adapter on the imaging camera according to your cameras mounting type.
6. Mount the camera on to the OAG in the correct position and lock the 3 screws.
7. The final setup.
8. Check that the prism does not block the imaging area.
9. Use the guiding screw to adjust the guiding cameras focus. This is best done during daytime to make sure both the imaging and guiding cameras can focus at the same position.
What's in the box
- OAG Body with M48 Telescope Adapter
- 1.25" Eyepiece / Camera Holder
- 5mm T2 Extension
- M42 Camera Adapter
- M48 Camera Adapter
- M42 Telescope Adapter
|Average Rating (3 Reviews): |Excellent quality from ZWO
Friday, 9 April 2021 | Paul
The ZWO off-axis guider is a lightweight, well constructed instrument. It was easy to incorporate into my current set up, simply replacing the 16.5mm spacer between my Skywatcher ED80 telescope and filter wheel. It arrived promptly from FLO in their usual high standard of packaging.
However in use things proved more tricky. Whereas my ZWO Miniscope picks up lots of stars and I get guiding straightaway, there are of course fewer stars with the OAG. Guiding with the ASIair, and ASI120MM guide stars are getting lost. I am still experimenting, but suspect unless you have a really dark sky the prospective guide star quickly gets lost in the 'murk' of light pollution etc. So the OAG loses a star in this review!
Saturday, 12 December 2020 | Nigel
I was having trouble with flexure using a WO 72mmX 420 guide scope, with my 8" edge HD. This was easy to install and immediately solved the problem. The guide stars look like bananas but is not effecting the guiding performance. I am using the asi120mm guide camera and need to run it with a very high gain to get more guide stars. The guiding figures are the same for both OAG and guide scope but my stars are now round and zero field drift.
Wednesday, 29 January 2020 | Trevor
I married this OHG to an Atik EFW2 filter wheel. I contemplated drilling and tapping the OHG body to make use of the three screws in the EFW. These screws are the ones used by Atik for their OHG.
In the end I ordered an male/female thread adapter from Flow. To be able to fix the orientation of the guide camera by setting the height of these three screws. Focusing has been initially set in daylight using a distant tree so we are waiting for clear night for further focusing and testing.
Please fill in the form below to ask a question.
Q1. How can I remove flex / wobble with the Prism stalk of my ZWO OAG?
Once you have adjusted the ZWO to be parfocal with the Imaging camera and have the Prism stalk adjusted to the position you require then you can tighten the two grub screws, one on the OAG body and one on the stalk, to remove any flex/wobble
The Allen keys required are supplied with the OAG