Astronomy Specialist

ZWO OFF AXIS GUIDER

$219.00 AUD
SKU: ZWO-OAG

ZWO


 

This off-axis guider offers the best solution for guiding as it eliminates the problem of the differential flexure. This effect can arise when a guiding scope is used: while a camera is capturing an image with the main telescope, the guiding scope can flex to a different amount causing a guiding error. In other words, the guiding telescope does not compensate for the mechanical movement of the main telescope during the exposure and as a result, the image can be blurred. An off-axis guider is installed on the main telescope before the camera so this problem does not occur as the guiding and imaging telescope are actually the same instrument. 

The ZWO off-axis guider uses a prism that deviates part of the light from the main telescope and redirects it to the guiding camera. However, it will not block any light to the sensor or create any shadow if oriented on the right way. For telescopes with long focal lengths, a guiding camera with a large sensor is recommended such as the ASI174MM Mini.

The large 8mm x 8mm prism allows to get a large field of view for the guiding camera. That means a wider field of view and therefore higher chances to have a suitable star for guiding.  

The off-axis guider reduces the overall weight of the telescope as the guiding telescope is not necessary.

  

Telescope connection
M48 x 0.75, M42 x 0.75 (with adapter)
Camera connection M48 x 0.75, M42 x 0.75
Sensor size compatibility APS-C and smaller
Compatible guide cameras
1.25" barrel cameras, ZWO non-cooled cameras
Guide camera interface
1.25" barrel, M42 x 0.75
Optical thickness 16.5 mm
SKU ZWO-OAG

 


1. If you use a field flattener or a coma corrector that requires a specific distance to the sensor, calculate the necessary spacing first.

2.Remove the prism and connect the body of the OAG to the telescope.

ZWO OFF AXIS GUIDER3. Insert the prism in the OAG 

ZWO OFF AXIS GUIDER

 

4. Connect the guiding camera

ZWO OFF AXIS GUIDER

5. Connect the T2 (M42 or M48) adapter to the main camera.

ZWO OFF AXIS GUIDER

6. Connect the camera to the OAG and lock the 3 thumb screws. Check that the prism is positioned on an angle that would not block the imaging area.

ZWO OFF AXIS GUIDER

 ZWO OFF AXIS GUIDER

7. Focus with the main camera and then slide the prism along with the guiding camera in order to reach the focus. 

ZWO OFF AXIS GUIDER

 

 

  • OAG body (with 1.25″ barrel, 5mm extender with M42 thread)
  • M48 adapter for main imaging camera
  • M48-M42 adapter 
  • Hex key

 

 

Customer Reviews

Based on 2 reviews
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F
Ferenc
Game changer

Easy to set up. Using on my Askar 80phq with a zwo 120 mm mini. It is working perfectly. For me it was a game changer, the guiding is perfect, way above expectation.

G
Greg England
Nice and compact

Works well with APC and smaller sized sensors, using the unit on my Skywatcher 190MN between the filter holder and telescope which provides the perfect spacing between scope and camera for prime focus photography. Excellent and speedy service as always.