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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Starlight Instruments 2.5" Adapter for Celestron C11/C14 SCT Telescopes
Starlight Instruments 2.5" Adapter for Celestron C11/C14 SCT Telescopes
Starlight Instruments 2.5" Adapter for Celestron C11/C14 SCT Telescopes

Starlight Instruments 2.5" Adapter for Celestron C11/C14 SCT Telescopes

by Starlight Instruments
SKU SI-A25-2003-15
$250.00 - $250.00
$250.00
$250.00 - $250.00
$250.00
Price Match Policy!
  • Adapts 2.5" Feather Touch Focusers
  • Compatible with Celestron C11 Telescopes
  • Compatible with Celestron C14 Telescopes
  • Threads Directly to SCT Rear Cell
  • Enables High-Precision External Focusing
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  • Description
  • FAQ
  • Downloads
  • Warranty

  • Starlight Instruments 2.5" Adapter for Celestron C11/C14 SCT Telescopes

    This Starlight Instruments adapter provides the critical mechanical interface for mounting a 2.5" Feather Touch focuser onto the rear cell of Celestron C11 and C14 Schmidt-Cassegrain telescopes. Machined for a perfect fit, it allows these large SCTs to utilize the robust helical rack-and-pinion drive of a 2.5" Starlight focuser, eliminating the image shift inherent in the stock mirror focusing mechanism.

    Securely Mating a 2.5" Focuser to C11/C14 Rear Cells

    This adapter creates a rigid, non-flexing connection between your telescope and a Starlight Instruments 2.5" focuser. It threads directly onto the large-format rear cell threads of a Celestron C11 or C14, providing a stable platform that prevents tilt or sag, even with heavy imaging equipment. The precise machining ensures perfect optical alignment, maintaining the performance of your telescope's optics.

    Enabling Precise, Shift-Free Focusing for C11/C14 Imaging

    The primary reason to upgrade a C11 or C14 with an external focuser is to eliminate "mirror shift"—the slight image jump caused by the telescope's internal focusing mechanism. This adapter is the first step in that upgrade. By installing a 2.5" Feather Touch focuser, you can lock the telescope's primary mirror and achieve exceptionally fine, repeatable focus adjustments externally.

    This setup is essential for serious astrophotography, where even minor focus shifts can ruin an exposure. It provides the stability needed to support a full imaging train, including a camera, filter wheel, and off-axis guider, without introducing flexure into the optical path. Your C11 or C14 becomes a far more capable imaging platform, ready for high-resolution planetary work or deep-sky astrophotography.

  • What is the purpose of this Starlight Instruments 2.5" adapter for C11/C14 telescopes?

    This adapter's sole purpose is to connect a 2.5" Starlight Instruments Feather Touch focuser to the rear cell of a Celestron C11 or C14 SCT. It provides the correct threads and a rigid mechanical connection, allowing you to bypass the telescope's stock focuser.

    Will this adapter fit my Celestron 11" EdgeHD telescope?

    Yes. Both the standard (orange tube) and EdgeHD versions of the Celestron C11 and C14 telescopes use the same large-format rear cell thread, so this adapter is compatible with both optical designs.

    Why do I need this specific adapter to install a Feather Touch focuser on my C14?

    Telescopes and focusers have different mechanical interfaces. This adapter is purpose-built to match the specific rear thread of a Celestron C11/C14 on one side and the mounting pattern of a Starlight Instruments 2.5" focuser on the other, ensuring a secure and perfectly aligned fit.

    How does using this adapter and a 2.5" Feather Touch focuser help with imaging Jupiter with my C11?

    High-resolution planetary imaging of targets like Jupiter requires extremely precise focus. The internal focuser on a C11 can cause the image to shift when making fine adjustments, making it difficult to achieve critical focus. By using this adapter and a Feather Touch focuser, you can make minute, backlash-free adjustments without any image shift, resulting in sharper and more detailed planetary images.

    Can I use this adapter to attach other accessories besides a 2.5" focuser to my C14?

    No, this adapter is designed specifically to mount a Starlight Instruments 2.5" focuser. It is not a general-purpose adapter for other accessories, which may have different mounting requirements.

    After installing this adapter and focuser on my C14 for imaging the Whirlpool Galaxy (M51), how do I focus?

    The recommended workflow for imaging M51 is to first use the C14's stock focusing knob to achieve a rough focus, and then lock the primary mirror in place if your telescope has mirror locks. From that point on, you will use only the external 2.5" Feather Touch focuser for all fine focusing adjustments, either manually or with a motor drive. This prevents mirror shift from affecting your long exposures.

  • Starlight Instruments 2-Year Warranty