Celestron Off Axis Guider (OAG)

Celestron Off Axis Guider (OAG)
Celestron Off Axis Guider (OAG)Celestron Off Axis Guider (OAG)Celestron Off Axis Guider (OAG)
Celestron Off Axis Guider (OAG)Celestron Off Axis Guider (OAG)


In stock - Shipped 1-2 working days.

Model:  celestron-off-axis-guider-sct
Part Number:  93648
Brand:  Celestron


Celestron 2 Year Warranty

Celestron products include a two year warranty except binoculars and spotting scopes which have limited lifetime warranties.

An Off-Axis Guider is an astroimaging accessory considered by many to be the most accurate method of autoguiding. 

The Celestron Off-Axis Guider uses a large 12.5mm prism to intercept a small portion of the telescope’s focal plane (outside the field of view of the main imaging camera) to locate a guide star. Any movement seen by the guide star will be the exact same movement seen by the imaging camera. Guiding this way will correct for tracking errors, as well as opto-mechanical errors or flexure, for pinpoint round stars.

Off-Axis Guiders have been around for a long time, but typically pose three main challenges:

  • Finding a guide star from the far edges of the telescope’s focal plane can be difficult, considering the small field of view and sometimes less-than-ideal illumination.
  • Getting both imaging camera and autoguider to reach focus with one another is time consuming and sometimes requires experimentation.
  • Additional spacers and adapters are usually required for your particular camera, telescope, and autoguider, which adds to cost and complexity.

Celestron's Off-Axis Guider addresses these challenges by:

  • Providing a large 12.5mm prism that can be adjusted to move closer to the center of the telescope’s focal plane, depending on the size of the imaging camera. This results in brighter guide stars, with the help of the large prism to fully illuminate the autoguider sensor.
  • Featuring a high-quality, fixed-orientation Helical focuser. This provides extremely smooth and accurate focus of the autoguider without changing (or twisting) the autoguider camera orientation.
  • Including all the needed spacers and adapters are included for most common imaging configurations, including DSLR cameras, Nightscape CCD cameras, and more. The following adapters are included: SCT/EdgeHD, female M48, female M42 (T-thread), male M48, male M42 (T-thread), 3 T-thread spacers

NOTE: The Celestron Off-Axis Guider is not compatible for DSLR imaging with the 8" EDGE-HD Focal Reducer. 

Product Specifications

Weight 510g
Clear Aperture 48mm (1.89 inches)
Helical Focuser Travel 8mm
Telescope Connection M42 T-thread, M48, and SCT/EdgeHD
Autoguider Connection M42 T-thread, and standard 1.25" adapter
Camera Connection M42 T-thread, and M48

The following manuals and downloads are available for this product:

Celestron Off Axis Guider Instruction Manual

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