ZWO Large Off-Axis Guider for ASI461MM-P Camera - OAG-L-68
A Large OAG Specifically for Your ASI461MM Pro Camera!
ZWO has designed this large off-axis guider to work specifically with the ASI461MM Pro camera and the ZWO 50 mm Square filter wheel. This OAG is simple to use and is perfect for those looking to do long focal length astrophotography. Much like the standard ZWO Large OAG, the OAG-L-68 has a prism size of 12x12mm. The body of the ZWO OAG is made of high-quality materials, allowing it to be lightweight yet sturdy. It comes with a 17.5 mm thickness.
The effective light aperture of this ZWO ASI461 OAG is 11.7mm x 8.3mm. This larger clear aperture provides a wider field of view while guiding, a perfect pair for the ZWO ASI461MM Pro's massive medium format sensor! This OAG can be used to connect the main camera and guide camera simultaneously, allowing you image and guide with the same optical path and ditch additional guidescopes. If you're looking to build a high performance imaging train with one of the most incredible mainstream cameras of 2025, then this excellent optical path add-on is for you!
A Lightweight and Easy-to-Use Tool to Help You Reach Your Imaging Goals!
We want you to get the most out of your purchase. Read on below to learn how to get started with your ZWO OAG-L for ASI461MM Pro Cameras.
Operation Guide
When compared to the original OAG-L, this OAG has a larger prism size and there are no threads, allowing you to use the screws to connect it to other equipment. If the thread on the telescope side is M48, then you do not need to remove the included M48 sensor tilt plate. If the telescope thread is not M48, then you will need to remove the supplied tilt plate and attach a user-supplied tilt plate that comes with a corresponding thread. When you add the OAG-L to your optical train, please make sure that the prism does not block the ASI461MM Pro camera sensor. Using the guiding screw to adjust the guiding camera's focal length, make sure the distances from the prism to the main camera and to the guide camera are the same. It is most often better to do this during the day or in good light, as it can be difficult in dark conditions.
Adjusting the Prism
Adjusting the height of your OAG-L-68 prism requires just a hex wrench and bit of patience! Start by removing the OAG from your telescope. Then begin loosening the M4 screw, accessible through a hole in the sensor tilt plate. Once loose, pinch the prism on both sides and move it up or down until it is at the desired height; being careful not to touch and smudge the front of the prism. Once you have the prism where you want it, retighten the M4 screw to lock the prism in place!