The off-axis guider offers your a simple method of autoguiding your telescope for astrophotography. There is no need to mount a guidescope, rather a guiding camera tracks stars which are deflected from the telescope's optical path close to the imaging camera's sensor.
An advantage of this method is that the guide stars are located within the area of sky close the astrocamera. So you track the stars which are next to your desired object and avoid errors caused by differential flexure and guidescope misalignment.
This large off-axis guider comes with larger prisms. The OAG's wider clear aperture compared with other models provides a larger visual field when guiding. It is easy to use and designed for users who are interested in photography with longer focal lengths. In order to enjoy the full benefits of this accessory, ZWO recommends using it with a full-frame camera.
The OAG-L comes with a M48 tilting plate. This helps to precisely align the focal plane with the sensor.
Optical path with tilting plate (5mm), optional EFW (20mm) and optional cooled camera (12.5mm): 55 millimetres
- For guiding, the OAG-L can only be used with ASI Mini cameras such as the ASI174MM Mini, the ASI290MM Mini and the ASI120MM Mini.
- If the OAG-L is used without a filter wheel, the ZWO D70-M54F adapter must be used to connect the off-axis guider to the camera and achieve a 55mm backfocus.
- If your telescope has an M48 thread, you can connect the OAG-L using the M48 tilting plate adapter. Otherwise, you need to remove it and use a different tilting plate adapter on the relevant thread of your telescope.
- Off-axis guider
- M48 tilting plate (pre-mounted)