ZWO Off Axis Guider

An off-axis guider (OAG) eliminates differential flexure, a common issue where the guide scope and main telescope shift slightly relative to each other during long exposures. By using the same optical path as your main camera, the OAG ensures your guiding is perfectly aligned with your imaging sensor for sharper, more consistent results.

The unit features a slim 16.5 mm back focus, which is designed to fit into most standard imaging setups without requiring major adjustments. It uses an M42 thread and 1.25-inch interface, making it compatible with a wide range of cameras and telescope configurations.

The prism is compact at 8 x 8 mm, specifically sized to pick off enough light for your guide camera without obstructing the main imaging sensor. In most setups, you won't notice any impact on your primary field of view.

This OAG is designed to work with most dedicated planetary or guide cameras that accept a 1.25-inch nosepiece. For the best results, we recommend using a sensitive, small-format guide camera to ensure you can easily find a suitable guide star within the prism's field.

The 16.5 mm back focus is a fixed mechanical requirement of the OAG body itself. When planning your imaging train, you must account for this distance to ensure your main camera can reach focus properly.