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Starizona M68 T-Adapter for Large Celestron SCTs

Starizona M68 T-Adapter for Large Celestron SCTs

by Starizona
SKU STZ-TAFH-M68
CA$140.00 - CA$140.00
CA$140.00
CA$140.00 - CA$140.00
CA$140.00
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  • Connects M68 accessories to large Celestron SCTs
  • Fits telescopes with 3.29" rear cell threads
  • Compatible with C11, C14, and C9.25 EdgeHD models
  • Provides 91mm of optical length
  • Achieves 55mm backfocus on systems requiring 146mm
  • Features a large 65mm clear aperture
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • M68 T-Adapter for Large Celestron SCTs

    This Starizona M68 T-Adapter connects large off-axis guiders to Celestron SCTs with 3.29" rear cell threads, including all C11, C14, and C9.25HD models. The adapter provides a precise 91mm optical length, establishing the standard 55mm of backfocus for a camera train on optical systems that require 146mm total backfocus. A generous 65mm clear aperture, which stops down to 62mm at the end cap, prevents vignetting even with large format sensors.

    Secure M68 OAGs to 3.29" Celestron Rear Cells

    Designed for imagers using larger off-axis guiders (OAGs) or accessories with M68 threads, this adapter creates a rigid, wide-aperture connection to your telescope. It attaches directly to the large 3.29" threads found on the rear cell of all Celestron C11 and C14 models, both standard and EdgeHD, as well as the C9.25 EdgeHD. This direct-threaded attachment is critical for eliminating flexure and maintaining collimation with heavy imaging trains.

    A 91mm Optical Length for 55mm Backfocus Systems

    Achieving correct spacing is non-negotiable for sharp, coma-free images. This adapter consumes exactly 91mm of the optical path. For systems with a 146mm backfocus requirement—such as EdgeHD telescopes at f/10, an EdgeHD with the 0.7x reducer, or an SCT with Starizona's SCT Corrector LF—this leaves the industry-standard 55mm of remaining distance for your camera and accessories. The internal 65mm clear aperture ensures the light cone from the telescope is unobstructed, preserving brightness and image quality at the sensor.

    Upgrade Path from the Starizona M42/48/54 Adapter

    This M68 T-Adapter shares an identical body and lock ring with Starizona's M42/48/54 large T-adapter with filter holder. If you already own that component and are upgrading your OAG to a larger M68 model, you do not need to purchase this entire assembly. The M68 end cap is available separately, allowing for a cost-effective transition to the larger thread size while reusing your existing adapter body.

  • Which Celestron telescopes are compatible with the Starizona M68 T-Adapter?

    The Starizona M68 T-Adapter is compatible with any Celestron telescope that features the large 3.29" rear cell thread. This includes all C11 and C14 models (both standard SCT and EdgeHD) and the C9.25 EdgeHD. It is not compatible with smaller telescopes like the C8 or C9.25 standard SCT, which use a smaller 2" rear thread.

    What is the clear aperture of the Starizona M68 T-Adapter?

    The adapter has a clear aperture of 65mm for most of its length to prevent vignetting. This steps down slightly to 62mm at the M68 end cap itself.

    How does the Starizona M68 T-Adapter help achieve the correct 55mm backfocus?

    The adapter has a fixed optical length of 91mm. When used on a system with a total backfocus requirement of 146mm (like an EdgeHD with a reducer), it consumes 91mm of that distance. This leaves exactly 55mm of remaining backfocus, which is the standard spacing required for most DSLRs with a T-ring, and many dedicated astronomy cameras when paired with filter wheels or OAGs.

    I have a C8 EdgeHD. Will the Starizona M68 T-Adapter fit my telescope?

    No. The Celestron C8 EdgeHD uses a smaller 2" SCT thread on its rear cell. This Starizona M68 T-Adapter is designed exclusively for the larger 3.29" threads found on the C9.25HD, C11, and C14 models.

    Can I use the Starizona M68 T-Adapter with my C14 EdgeHD and the 0.7x reducer?

    Yes. The C14 EdgeHD with the 0.7x reducer has a backfocus requirement of 146mm. The 91mm optical length of the Starizona M68 T-Adapter is designed specifically for this configuration, leaving you with the standard 55mm of spacing for your camera train.

    I already own Starizona's M42/48/54 T-adapter. Do I need to buy this entire M68 T-Adapter?

    No, you may not need the full assembly. The main body and lock ring of this M68 adapter are identical to the M42/48/54 version. Starizona offers the M68 end cap as a separate part, allowing you to upgrade your existing adapter to support M68 accessories without replacing the entire unit.

  • Adapter Type T-Adapter
    Accessory Connection M68 x 1 Female Threads
    Telescope Connection 3.29" Female Threads
    Telescope Compatibility Celestron C11 (SCT/EdgeHD), C14 (SCT/EdgeHD), C9.25 (EdgeHD)
    Optical Length 91mm
    Clear Aperture 65mm (main body), 62mm (at end cap)
    Backfocus Usage Consumes 91mm, leaving 55mm on systems with 146mm total backfocus
    Recommended Systems EdgeHD at f/10, EdgeHD with 0.7x Reducer, SCTs with Starizona SCT Corrector LF

    • M68 T-Adapter for Large Celestron SCTs

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  • Starizona Warranty