An Off-Axis Guider (OAG) allows you to have an autoguide camera share the same optical path as the main camera. This solves the problem of flexure that can ruin your images. Because the telescope mount rotates your equipment, gravity acts in different directions. This means that a heavy guide can move fractionally in relation to the main scope. This problem is only made worse when using long focal length scopes, such as Schmidt-Cassegrains. An OAG therefore will give you more accurate guiding and better shaped stars.

This size of the ToupTek Off-Axis guider comes with the 54mm threaded ring on the telescope side. This matches the thread on your coma corrector, field flattener, or nose piece. The body of the OAG and the mounting ring comes to 17.5mm. This body bolts to a 20mm spacer which bolts to the front of a deep-sky camera (with back-focus of 17.5mm) using six bolts. Overall, the train places the camera sensor 55mm from the corrector flange. If you are using a filter wheel, this replaces the 20mm spacer.

This extra-large version of the off-axis guider has an expanded prism, giving your guide camera a larger field of view to find more guide stars. This is necessary for users of guide cameras with large sensors such as the IMX174, IMX585 or IMX482.

The ToupTek OAG includes a helical focuser with a thumb screw to lock the position. The focuser will not rotate the guide camera, meaning you won’t have to recalibrate the autoguiding program if you refocus the OAG.

Note: The OAG-X is only compatible with GPM and G3M series guiding or planetary cameras.