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Celestron Off-Axis Guider (OAG) for SCTs and EdgeHD Series Telescopes

SKU : CE-93648

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  • Fixed-Orientation Helical Focuser.
  • The Most Accurate Way to Guide.
  • Multi-Coated Prism with Aluminized Backing.
  • Includes Adapter for various cameras.
  • Ideal for Schmidt-Cassegrain and EdgeHD Telescopes.
  • Note: If using a full frame sensor camera like the ZWO ASI6200 or QHY 600, an additional adapter is required to provide a fully-illuminated image circle with no vignetting.


Product Details

  • The Celestron Off-Axis Guider is an essential astro-imaging accessory for long focal length telescopes that require the most accurate guiding possible. The Celestron Off-Axis Guider uses a large 12.5mm prism to intercept a small portion of the telescope's light (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 optomechanical errors or flexure. The result: better astro-images with pinpoint round stars.

      Solutions of the Celestron Off-Axis Guider

      • It provides a large 12.5 mm prism that can be adjusted to move closer to the center of the telescopes 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 an extremely smooth and accurate focus of the autoguider without changing (or twisting) the autoguider camera orientation.
      • 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 adapters.

      Celestron Off-Axis Guider Specifications

      • Weight: 18 ounces.
      • Clear Aperture: 48 mm.
      • Helical Focuser Travel: 8 mm.
      • Telescope Connection: M42 T-thread, M48, and SCT/EdgeHD.
      • Autoguider Connection: M42 T-thread, and standard 1.25-inch adapter.
      • Camera Connection: M42 T-thread, and M48.
      • For setup and configuration, please refer to the Celestron OAG manual on Celestron's website.

      Celestron Product Number: 93648

    1. specifications

      Free ShippingYes
    2. included items

      • Celestron's Off-Axis Guider.
      • 12.5 mm Multi-Coated Prism.
      • Fixed-orientation helical focuser.
      • Adapter: SCT/EdgeHD.
      • Adapter: female M48.
      • Adapter: female M42 (T-thread).
      • Adapter: male M48.
      • Adapter: male M42 (T-thread).
      • Adapter: (3) T-thread spacers.



    Product Reviews

    Customer Reviews
    4.8 Based on 5 Reviews
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    Filter Reviews:
      Marvin C.
      United States

      Worth the money

      I was having a difficult time getting another brand OAG to see the guiding stars. With all the available accessories, it was easy with the Celestron OAG.

      United States United States

      Celestron Off-Axis Guider

      excellent as advertised

      Lee M.
      United States United States

      Great and fairly simple to use for an OAG

      First, the unit is huge, but allows for an easy adjustment of guider position and camera orientation. I use a Canon 5D Mkii DSLR and ZWO ADI174mm Mini guide scope and connecting them both was easy, only needing an M48 T-adapter setup. The depth of the DSLR and thickness of the domed OAG adapers required raising the guidescope almost to the top even with the 25mm nosepiece to achieve parafocus. But, it was attainable and the prism reflected plenty of light for the guidescope to find stars easily. Many configuration adapters are provided for versatility (M42, M48 etc). Note that the OAG can be assembled backwards as the interface on both sides of the OAG body are the same. So pay attention to the orientation of the prism.

      Marvin C.
      United States United States

      Celestron Off Axis Guider

      It has been a great experience. The unit is massive compared to others and has a smooth guide focus without having to twist the guide camera around in the focusing process.

      Steven C.
      United States United States

      Nice but huge

      This is a very nice OAG, but be aware it is very wide. The body is the stated 29mm, but the adapters front and rear will add another 15 or 20 mm. Otherwise, solid, nicely made and comes with lots of adapters. The focuser is very nice.