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SBIG OAG-8300 Off Axis Guider

by SBIG
SKU DL-OAG-8300
CA$863.00 - CA$863.00
CA$863.00
CA$863.00 - CA$863.00
CA$863.00
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  • Designed for SBIG ST-8300 and STF-8300 cameras
  • 7-element relay optics with a 0.7x focal reducer
  • Adds only 22.9 mm of optical length to the imaging train
  • Rotatable 1.25-inch drawtube for the SBIG ST-i guide camera
  • Weighs 356 g
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • SBIG OAG-8300 Off Axis Guider

    The SBIG OAG-8300 Off Axis Guider transforms ST-8300 and STF-8300 cameras into fully integrated, self-guiding imaging systems. Its unique 7-element relay optics incorporate a 0.7x focal reducer, effectively doubling the guide camera's field of view to make finding a suitable guide star simple. By adding only 22.9 mm of optical path length, the OAG-8300 provides precise, flexure-free guiding without consuming critical back focus, all while weighing just 356 g.

    Integrated Guiding for ST-8300 and STF-8300 Cameras

    Designed as a dedicated accessory, the OAG-8300 bolts directly to SBIG's FW5-8300 or FW8-8300 filter wheels, or directly to the camera body using an optional spacer. This rigid, all-threaded connection eliminates the potential for flexure that can occur with separate guide scopes, ensuring your main camera and guide camera move as a single, solid unit. It is specifically engineered for use with the SBIG ST-i guide camera, for autoguiding with KAF-8300 cameras.

    7-Element Relay with 0.7x Focal Reduction

    The core of the OAG-8300 is its sophisticated 7-element optical relay. This system moves the guide camera's focal plane to the side of the main camera body while simultaneously reducing the focal length by a factor of 0.7x. This reduction doubles the field of view for your guide camera, increasing the number of available guide stars in any given patch of sky and minimizing the need to hunt for a suitable star.

    A Low-Profile 22.9 mm Optical Length

    Back focus is a critical resource in any imaging train, and the OAG-8300 is engineered to conserve it. The entire assembly adds only 22.9 mm of optical length, allowing you to incorporate it into setups with correctors, reducers, or other accessories without running out of focuser travel. This slim profile is made possible by the internal relay optics, which move the guide camera to the side of the imaging camera.

    Adjustable Prism and Rotatable 1.25" Port

    The OAG-8300 provides critical adjustments to optimize guiding across different telescopes. The internal pickoff prism can be moved to accommodate optical systems from f/5 to f/10, ensuring it samples stars from the edge of the corrected field without casting a shadow on the main KAF-8300 sensor. Additionally, the 1.25" drawtube for the ST-i guide camera can be rotated to orient the guide sensor and manage cables for a snag-free setup.

  • Which SBIG cameras is the OAG-8300 compatible with?

    The SBIG OAG-8300 is designed specifically for all SBIG ST-8300 and STF-8300 camera models, which are built around the KAF-8300 sensor. It is designed to use the SBIG ST-i guide camera as the autoguider.

    Do I need a filter wheel to use the SBIG OAG-8300?

    No, but if you are not using an SBIG FW5-8300 or FW8-8300 filter wheel, you must use the optional Filter Wheel Spacer accessory. This spacer is required to place the OAG-8300 at the correct distance from the main sensor, allowing the ST-i guide camera to reach focus.

    How does the 0.7x reducer in the OAG-8300 help find guide stars?

    The integrated 0.7x focal reducer effectively doubles the field of view of the attached ST-i guide camera. This wider perspective makes it significantly easier to find a suitable guide star near your imaging target without compromising the centering of your target.

    How much back focus does the SBIG OAG-8300 use?

    The SBIG OAG-8300 adds only 22.9 mm of optical length (back focus) to your imaging train. This minimal profile is a key advantage, leaving ample room for other accessories like focal reducers or field flatteners.

    Will the OAG-8300's pickoff prism cast a shadow on my main sensor?

    The pickoff prism is adjustable to prevent this. For faster optical systems (around f/5), the prism is positioned further out, while for slower systems (like an f/10 SCT), it is moved further in. This allows you to place the prism at the very edge of the light cone to pick up guide stars without vignetting the main KAF-8300 sensor.

    How do I attach the OAG-8300 to my telescope?

    The OAG-8300 comes with one front adapter plate, in T-thread (M42x0.75), 2-inch SCT visual back (2"-24tpi) or STL (2.156"-24) thread. Use the largest adapter you can accommodate to avoid vignetting.

  • Optical Design 7-element relay with 0.7x focal reducer
    Optical Length 22.9 mm
    Max Recommended Main Sensor KAF-8300 cameras: ST-8300 and STF-8300
    Telescope Connection M42x0.75 (T2), SCT 2in-24tpi
    Guide Camera Port 1.25" rotatable drawtube for SBIG ST-i guide camera
    Weight 356 g
    Length 165 mm
    Warranty 1 year

    • OAG-8300 off-axis guider

      × 1

    • Front adapter plate (T-thread, 2in or STL)

      × 1

    • Three 4-40 x 1in screws

      × 1

    • Four 4-40 x 1/2in button head screws

      × 1

  • Diffraction Limited 1-Year Warranty