Skip to content
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" End Cap w/ 2.0" Compression Ring Opening and M47X.75 Thread

by Starlight Instruments
SKU SI-EC25-2005-5
$200.00 - $200.00
$200.00
$200.00 - $200.00
$200.00
Price Match Policy!
  • Adapts 2.5" Feather Touch focusers for visual and imaging use
  • Features a standard 2.0" opening with a non-marring brass compression ring
  • Includes a female M47x0.75 thread for secure accessory attachment
  • Machined from high-grade aluminum for rigidity and durability
Backordered
Request Stock Alert
Availability Info
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Warranty

  • Starlight Instruments 2.5" End Cap w/ 2.0" Compression Ring Opening and M47X.75 Thread

    The Starlight Instruments 2.5" End Cap outfits a 2.5" Feather Touch focuser with both a 2.0" compression ring opening and a female M47x0.75 thread. With this dual design, you can switch between standard 2.0" eyepieces and specific M47x0.75 threaded imaging accessories without changing hardware on your optical tube.

    A Dual-Purpose End Cap: 2.0" Compression and M47x0.75 Threads

    This end cap integrates two common connection standards into a single, precision-machined component for your 2.5" Feather Touch focuser. For visual observation, the 2.0" opening uses Starlight Instruments' signature brass compression ring to securely grip your diagonal or eyepieces without scratching their barrels. For astrophotography, the female M47x0.75 thread provides a rigid, direct-threaded connection for compatible field flatteners, reducers, or camera adapters, ensuring your imaging train remains perfectly aligned.

    M47x0.75 vs. Standard 2" End Caps: The Imaging Advantage

    While a standard 2.0" compression ring end cap can hold a camera via its 2" nosepiece, this slip-fit connection is susceptible to tilt and flexure, especially with heavier cameras. The primary advantage of this M47x0.75 threaded end cap is the elimination of that risk. By threading your corrector or camera directly to the focuser drawtube, you create a solid, stable connection that preserves the optical alignment critical for achieving sharp, round stars across the entire field of view.

  • Which Starlight Instruments focusers is this 2.5" End Cap compatible with?

    This end cap is designed specifically for Starlight Instruments 2.5" Feather Touch focusers, such as the FTF25xx series. It provides a direct replacement for other 2.5" end caps.

    What is the main benefit of the M47x0.75 thread on this End Cap?

    The M47x0.75 thread allows for a rigid, secure connection to imaging accessories like field flatteners, reducers, and cameras. This threaded attachment prevents tilt and flexure that can occur with slip-fit compression rings, which is essential for critical astrophotography.

    Can I still use my 2.0" eyepieces and diagonal with this M47x0.75 threaded End Cap?

    Yes. The end cap features a standard 2.0" opening with a brass compression ring, allowing you to use all your standard 2" visual accessories just as you would with a non-threaded end cap.

    Why does Starlight Instruments use a brass compression ring in this 2.5" End Cap?

    Starlight Instruments uses a soft brass compression ring to securely hold your eyepieces and accessories. Unlike steel set screws that can dig into and damage the barrels of your equipment, the brass ring provides a firm, even grip that protects your investment from scratches and dents.

    How would this M47x0.75 End Cap benefit my setup with a large refractor and a 2.5" Feather Touch focuser?

    For a large refractor like a Takahashi or Astro-Physics equipped with a 2.5" Feather Touch focuser, this end cap is ideal. It provides a direct threaded path for specific reducers or flatteners that use the M47 thread, ensuring perfect optical spacing and alignment for a flat, corrected field from edge to edge.

    If I'm imaging planets with a Celestron EdgeHD 9.25 and a 2.5" Feather Touch, is this End Cap necessary?

    While a standard 2" compression ring works for planetary imaging, this M47x0.75 threaded end cap offers a more robust solution. If your camera train includes heavy components like a filter wheel and an ADC, the threaded connection provides superior rigidity, preventing any sag that could shift the focus point during an imaging run.

  • Starlight Instruments 2-Year Warranty