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ZWO Off Axis Guider


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  • This Off-Axis Guider (OAG) is used in conjunction with your main camera for accurate tracking of deep-sky objects.
  • Seamlessly connects with any ZWO camera.
  • The ZWO ASI120MM Mini is a perfect guide camera choice for this OAG.
  • 16.5 mm Thickness.
  • 8 x 8 mm Prism Size.

Product Details

  • The ZWO Off-Axis Guider is highly effective and efficient. A great choice for those looking to avoid weighing down their setup too much with the additional component.

    The Prism is a relatively large 8 x 8 mm, and due to how the OAG is designed you may mount it to your telescope, and then mount both your main imaging camera and your guide camera to this same OAG.

    This OAG is compatible with all ZWO ASI cameras, and a variety of telescope threading options can be adapted for or attached to with great flexibility. Once connected, you will find the bonds between this OAG and your telescope to be stiff and exceptionally stable, as firm and lasting as could be desired. This generally can also be applied to the connections to your cameras.

  • specifications

    Back Focus16.5 mm
    Free ShippingYes
    Warranty2 Year Warranty
  • included items

    ZWO Included Items

    • OAG body (with 1.25-inch holder and 5 mm extender and M42 adapter).
    • M48 adapter for main imaging camera (in the box).
    • M48-M42 adapter for the telescope and flat lens (in the box).
    • Hexagon wrench (in the box).

Product Reviews

Customer Reviews
4.5 Based on 17 Reviews
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Filter Reviews:
  • cdamera
  • ASI290mm
  • ES127
  • Mini
  • ASIAir Pro
  • works
  • focuser
Richard S.
United States

Simple and Solid

Few adjustments and screws make it a solid performer. This replace my Orion Thin OAG which was flimsy, had way too many screws.

Tyler P.
United States United States


Works amazing once you get the correct back focus and prism height. Currently using with asi174mm mini and have no trouble finding guide stars.

Spencer C.
United States United States

ZWO OAG- perfect!

Worked perfectly with my ES127 and ASI290mm mini. Guiding has been <.45” total each night. Perfect to run with the ASIAIR Pro as well.

OPT Telescopes ZWO Off Axis Guider Review
Ryan C.
United States United States

Solved all my Guiding Issues

My previous guiding setup had a separate guidescope, but I could never manage to get round stars. I had great guiding numbers but terrible stars. Whether it be differential flexure, focuser movement, or whatever, it wasn't working. The ZWO OAG fixed all this on the first night. I was able to get everything attached right away, and it only took a little fiddling to get the optical train completely set up. I see no issues with the prism wobbling; I'm not sure what's happening with other people. There are two set screws and two alan screws. I have all of them tight and there is absolutely no movement anywhere. I'm getting the same guiding numbers as the guidescope, but now my stars are perfectly round regardless of exposure time. No more differential flexure! I can now take ~1 hour exposures with round stars at 1800mm focal length, which is completely overkill and completely awesome. The only negative is the field of view is limited, and I wouldn't expect a sensor much bigger than the ASI 120/290 to be beneficial because the outer edges will be too vignetted. I haven't had a problem with finding guide stars using an ASI 290mm, but having a high sensitivity camera definitely is a must. Overall, I highly recommend this guider because it solved all my guiding issues!

Kirby S.
United States United States


Very good, tiny bit tough to get the focusing down but once it's dialed in, it's perfect.

A OPT Telescopes Customer
Ron K.
United States

I have 3 of these now

One on each scope setup.