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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 3.5" End Cap for SBIG and FLI 5 Series/CCD Camera & Filter Wheels
Starlight Instruments 3.5" End Cap for SBIG and FLI 5 Series/CCD Camera & Filter Wheels

Starlight Instruments 3.5" End Cap for SBIG and FLI 5 Series/CCD Camera & Filter Wheels

by Starlight Instruments
SKU SI-EC35-505-12
$190.00 - $190.00
$190.00
$190.00 - $190.00
$190.00
Price Match Policy!
  • Adapts 3.5" Feather Touch focusers
  • Provides a 3.0"x24tpi male thread connection
  • Designed for FLI Proline and 5 Series cameras
  • Compatible with select SBIG filter wheels
  • Ensures a rigid, non-flexing imaging train
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  • Description
  • FAQ
  • Warranty

  • Starlight Instruments 3.5" End Cap for SBIG and FLI 5 Series/CCD Camera & Filter Wheels

    This Starlight Instruments 3.5" end cap provides a rigid, direct-thread connection for your imaging train, featuring a 3.0"x24tpi male thread. It is specifically designed to attach heavy cameras like the FLI Proline 16803 or SBIG and FLI 5 Series filter wheels directly to a Starlight Instruments 3.5" Feather Touch focuser, eliminating the potential for tilt or flexure inherent in compression-fit adapters.

    The 3.0"x24tpi Secure Imaging Interface

    For serious astrophotography, a threaded connection is non-negotiable. This end cap replaces the standard compression ring on a 3.5" Feather Touch focuser with a precise 3.0"x24tpi male thread. This solid metal-on-metal interface ensures your entire imaging train — from the filter wheel to the CCD camera — is held perfectly square to the optical axis, preventing image-destroying tilt that can ruin long exposures.

    Designed for FLI 5 Series and Proline 16803 Cameras

    This adapter is machined to mate directly with the threads found on specific high-end imaging equipment. It provides the correct interface for attaching an FLI Proline 16803 CCD camera or filter wheels from the FLI 5 Series. This removes any guesswork or the need for additional, potentially flexing adapters, creating the shortest and most rigid connection possible between your large-format camera and your Starlight Instruments focuser.

  • What is the advantage of using this Starlight Instruments 3.5" threaded end cap over a standard compression ring adapter?

    A threaded connection provides a much more secure and rigid attachment for your camera and filter wheel. Unlike compression rings that can allow for slight misalignment or sag under heavy loads, the 3.0"x24tpi thread on this end cap ensures your entire imaging train is held perfectly orthogonal to the focuser drawtube, eliminating a common source of tilt and elongated stars.

    Will this end cap fit my Starlight Instruments 2.5" or 3.0" focuser?

    No, this end cap is specifically designed to thread onto the drawtube of a Starlight Instruments 3.5" Feather Touch focuser. It will not fit the smaller 2.0", 2.5", or 3.0" models.

    How does this 3.0"x24tpi end cap prevent tilt with my FLI Proline 16803?

    The FLI Proline 16803 is a substantial camera. By threading it directly to this end cap, you create a single, solid assembly with the focuser drawtube. This direct-thread path distributes the load evenly and prevents the camera from sagging or tilting, which is critical for maintaining a flat field and round stars, especially in the corners of the large sensor.

    Is this the correct adapter for attaching an FLI 5 Series filter wheel to my 3.5" Feather Touch focuser?

    Yes, this end cap is designed to provide the correct 3.0"x24tpi male thread required to connect to FLI 5 Series filter wheels and cameras. This ensures a direct, secure fit without the need for intermediate adapters.

    Does this Starlight Instruments end cap have collimation screws?

    This end cap is designed to create a solid, square mechanical connection. While some Starlight Instruments adapters include provisions for tilt adjustment, the primary goal here is rigid, fixed alignment. You should always verify the collimation of your entire optical train after installing any new component.

    What tools are needed to install this 3.5" end cap on my Feather Touch focuser?

    Installation is straightforward and typically requires no special tools. You simply unthread the existing end cap (such as a 2" compression ring adapter) from the focuser's drawtube by hand and then carefully thread this new end cap in its place until it is snug.

  • Starlight Instruments 2-Year Warranty