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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.
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 Stellarvue 80-115mm Refractors

by Starlight Instruments
SKU SI-A25-2003-4
$250.00 - $250.00
$250.00
$250.00 - $250.00
$250.00
Price Match Policy!
  • Connects 2.5" Starlight Instruments Feather Touch focusers
  • Designed for Stellarvue 80mm, 90mm, 102mm, 105mm, and 115mm refractors
  • Attaches to the optical tube via a precise M88.5x1 thread
  • Enables focuser upgrades for heavy imaging payloads
  • Machined by Starlight Instruments for a zero-flexure fit
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Starlight Instruments 2.5" Adapter for Stellarvue 80-115mm Refractors

    This Starlight Instruments adapter provides the critical mechanical link to upgrade your Stellarvue refractor with a 2.5" Feather Touch focuser. It is specifically designed to fit Stellarvue 80mm, 90mm, 102mm, 105mm, and 115mm models, connecting directly to the optical tube's native M88.5x1 male thread. By installing this component, you can replace the stock focuser with a heavy-duty Starlight Instruments model, eliminating image shift and providing the support needed for demanding astrophotography setups.

    Secure M88.5x1 Connection for 2.5" Feather Touch Focusers

    Machined to the exacting tolerances of Starlight Instruments, this adapter ensures a rigid, perfectly aligned connection between your telescope and focuser. The M88.5x1 thread is cut to match the factory specification of compatible Stellarvue optical tubes, guaranteeing a secure, screw-on fit without modification. This solid foundation is essential for realizing the full potential of a Feather Touch focuser, allowing you to carry heavy cameras, filter wheels, and off-axis guiders with no flexure or tilt.

  • How do I confirm this 2.5" adapter fits my Stellarvue refractor?

    This adapter is designed for Stellarvue refractors in the 80mm to 115mm aperture range that have an M88.5x1 male thread on the rear of the optical tube. You should verify your telescope's specific thread size before purchasing. It is compatible with models such as the SV80, SVR90, SVR102, SV105, and SV115.

    What is the purpose of this Starlight Instruments adapter?

    Its sole purpose is to allow you to replace your Stellarvue's stock focuser with a superior Starlight Instruments 2.5" Feather Touch focuser. This upgrade provides significantly smoother and more precise focusing, zero image shift, and a much higher load capacity for astrophotography equipment.

    Does this adapter allow the 2.5" Feather Touch focuser to rotate?

    Yes. Starlight Instruments 2.5" focusers are designed to rotate a full 360 degrees within their tube adapters. This adapter serves as that secure base, allowing you to loosen the focuser's thumbscrews, orient your camera to perfectly frame an object like the Andromeda Galaxy (M31), and then lock it down without losing focus.

    Is this adapter required to install a 2.5" Feather Touch on my Stellarvue 102mm refractor?

    Yes, if your Stellarvue 102mm refractor uses the M88.5x1 thread. A scope-specific adapter is always required to mount a Feather Touch focuser, as it creates the precise mechanical interface between the optical tube and the focuser body. This part is not optional for the upgrade.

    What tools are needed to install this adapter on my Stellarvue scope?

    Installation is typically straightforward and requires minimal tools. You will first need to unthread your stock focuser from the optical tube. Then, you simply thread this adapter onto the exposed M88.5x1 threads until it is snug. No special tools are generally required for the adapter itself, though you may need hex keys to attach the focuser to the adapter.

    Will this adapter introduce any tilt or flexure into my imaging train?

    No. Starlight Instruments machines these adapters from solid metal with extremely high precision to match both the telescope and the focuser. When installed correctly, it creates a rigid, non-flexing connection that is far more stable than most stock focusers, preventing tilt even with heavy imaging cameras.

  • Focuser Compatibility Starlight Instruments 2.5" Feather Touch Focusers
    Telescope Compatibility Stellarvue 80mm, 90mm, 102mm, 105mm, and 115mm Refractors
    OTA Thread Size M88.5x1

    • 2.5" Adapter for Stellarvue 80-115mm Refractors

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  • Starlight Instruments 2-Year Warranty