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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 PTFE Coupled Collar for 2.5" Feather Touch Focusers

Starlight Instruments 2.5" Adapter PTFE Coupled Collar for 2.5" Feather Touch Focusers

by Starlight Instruments
SKU SI-A25-2003-1
$160.00 - $160.00
$160.00
$160.00 - $160.00
$160.00
Price Match Policy!
  • Connects 2.5" Feather Touch Focusers to Telescopes
  • Precision 95x1mm Male Thread
  • Low Profile 0.9" Length
  • PTFE-Coupled Collar for 360° Rotation
  • Designed for the FTF25 Focuser Series
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Starlight Instruments 2.5" Adapter PTFE Coupled Collar for 2.5" Feather Touch Focusers

    This Starlight Instruments 2.5" adapter creates a direct, secure attachment for your 2.5" Feather Touch focuser using a precision-machined 95x1mm male thread. With a minimal length of just 0.9", it maintains a low profile in your imaging train while its integrated PTFE-coupled collar enables full 360° rotation of the entire focuser body.

    Secure 95x1mm Threaded Connection for FTF25 Focusers

    This adapter serves as the critical mechanical interface between your telescope and a Starlight Instruments FTF25 series focuser. The 95x1mm male threading ensures a rigid, zero-flex connection, preventing any tilt or sag that could compromise collimation, which is essential for astrophotography with heavy cameras and filter wheels.

    PTFE-Lined for 360° Smooth Focuser Rotation

    The core of this adapter is its PTFE-lined (Teflon) collar. This low-friction surface allows the entire 2.5" Feather Touch focuser to rotate a full 360° within the adapter with buttery smoothness. This lets you perfectly frame your target without having to rotate your camera or diagonal, and makes it easy to position the focus knobs for comfortable access regardless of your telescope's orientation.

  • What is the purpose of the Starlight Instruments 2.5" PTFE Coupled Collar Adapter?

    This adapter physically connects a 2.5" Feather Touch focuser (FTF25 series) to a telescope that has a corresponding 95x1mm female thread. Its primary feature is the PTFE-lined collar, which allows the entire focuser body to be rotated 360° for convenient framing and access to the focus knobs.

    I have a telescope with a 95x1mm female thread. Will this adapter let me install an FTF25 series focuser?

    Yes, absolutely. This adapter is specifically designed for that purpose. It will thread directly into your telescope's 95x1mm port and provide the correct interface to mount any focuser from the Starlight Instruments 2.5" FTF25 series.

    What does 'PTFE-Coupled' mean for this Starlight Instruments adapter?

    PTFE is the chemical name for Teflon. A 'PTFE-Coupled' or 'PTFE-Lined' collar means the inner surface of the adapter where the focuser sits is lined with this extremely low-friction material. This is what enables the smooth, effortless 360° rotation of the focuser body, even with a heavy imaging train attached.

    After installing my 2.5" Feather Touch focuser with this adapter, how do I rotate it to frame a galaxy like Andromeda (M31)?

    To rotate the focuser, you simply loosen the nylon-tipped thumbscrews on the focuser body that lock it into the adapter collar. Once loose, you can turn the entire focuser assembly to your desired orientation to best frame the Andromeda Galaxy (M31). Once you are satisfied with the framing, you tighten the thumbscrews to lock it securely in place.

    Does the 0.9" length of this adapter affect my ability to reach focus?

    Yes, any adapter adds to the optical path length. The 0.9" (approximately 22.9mm) length of this adapter consumes that much of your telescope's available back focus. For most telescopes with ample back focus, this is not an issue. However, if your imaging setup is already close to the focus limit, you should verify you have at least 0.9" of in-travel to spare.

    How is this adapter installed on my telescope?

    Installation is straightforward. First, you carefully thread the 95x1mm male end of the adapter into the female port on your telescope's rear cell until it is snug. Do not overtighten. Then, you insert the base of your 2.5" Feather Touch focuser into the adapter and secure it using the focuser's own locking thumbscrews.

  • Adapter Size For 2.5" Feather Touch Focusers
    Telescope-Side Thread 95x1mm Male
    Length 0.9"
    Mechanism PTFE-Coupled Rotating Collar
    Compatibility Starlight Instruments FTF25 Focuser Series

    • 2.5" Adapter with 95x1mm Male Thread

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  • Starlight Instruments 2-Year Warranty