ZWO Off Axis Guider Adapter, Mark II:

Please note, ZWO have re-designed their OAG earlier in 2018. We've now updated the product description and images to reflect these changes.

ZWO OAG Adapter features

• Lightweight and beautifully machined
• 16.5mm thickness
• Large prism: 8*8mm (actually, it's a mirror)
• Allows the use of a guide camera in off axis position next to the main imaging camera without the need for a guide scope.
• Flexible adaptation to your camera and telescope via  T2 (M42*0.75) and M48 threads
• Fully compatible with all ZWO ASI cameras, but please contact us about which ZWO cameras we recommend for guiding. (The ASI174 chip is a bit too big for this mirror, so there will be strong vignetting in the guide image, therefore we'd recommend to use cameras with smaller chip for guiding.)
• Good stability, stiff connection to the telescope

What's in the box (see above image):

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

Mechanical Diagram

Connection Diagram:

How to use it:

1.   start with caculating the correct required distance for your imaging train.

for example: you need to attach 21mm extender to ASI071 to reach 55mm back focus distance:17.5mm+21mm+16.5mm=55mm

2. Take off the guider prism part and attach OAG body to the telescope

3. Insert the prism part into the OAG body

4.  Mount the guide camera

5.   Screw the T2 or M48 adapter on the imaging camera according to your the mount type

6. Mount the camera on the OAG in correct position and lock the 3 thumb screws

7. Setup is complete

Note: please make sure the prism won’t block the imaging area

Use the guiding screw to adjust the guiding camera’s focus.

You’d better to do it during the day to make sure that the imaging camera and guiding camera can reach focus at the same position.