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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 3.5" End Cap for Takahashi Large Field Flattener

by Starlight Instruments
SKU SI-EC35-505-1
$160.00 - $160.00
$160.00
$160.00 - $160.00
$160.00
Price Match Policy!
  • Connects 3.5" Feather Touch focusers to specific Takahashi large field flatteners
  • Features a male M92x1 thread for a secure, rigid connection
  • Compatible with Takahashi TOA645 and TOA67 flatteners
  • Precision-machined from high-quality aluminum
  • Eliminates potential tilt and flexure from compression fittings
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  • Description
  • FAQ
  • Specifications
  • Warranty

  • Starlight Instruments 3.5" End Cap for Takahashi Large Field Flattener

    This Starlight Instruments End Cap provides a secure, direct-threaded attachment between a 3.5" Feather Touch focuser and the Takahashi TOA645 or TOA67 large field flatteners. Its male M92x1 thread ensures a rigid, zero-tilt interface, which is critical for maintaining precise optical alignment across the entire imaging train with heavy camera payloads.

    M92x1 Threaded Connection for Takahashi TOA645/TOA67 Flatteners

    For large-format imaging, a compression ring is a point of potential flexure. This end cap replaces the standard compression fitting on your 3.5" Feather Touch focuser with a solid M92x1 male thread, creating a metal-on-metal connection directly to the Takahashi TOA645 or TOA67 flattener. This purpose-built design eliminates sag and preserves the flat field delivered by your corrector.

    Precision Machining for a Rigid Imaging Train

    Machined from a single piece of high-grade aluminum and finished in-house, this end cap reflects the precision Starlight Instruments is known for. The exacting tolerances ensure perfect concentricity with the optical axis, preventing image shift during focusing. By creating a rigid, threaded column from the focuser drawtube to the flattener, you guarantee your imaging sensor remains perfectly orthogonal to the focal plane.

  • What is the purpose of the Starlight Instruments 3.5" End Cap for Takahashi?

    This end cap is designed to create a secure, threaded connection between a 3.5" Feather Touch focuser and a Takahashi TOA645 or TOA67 large field flattener. It replaces standard compression fittings to eliminate any possibility of tilt or sag in the imaging train, which is crucial for astrophotography.

    Which focusers is this M92x1 end cap compatible with?

    This end cap is specifically designed for the Starlight Instruments 3.5" Feather Touch focuser series. It will not fit 2", 2.5", or 3" models.

    How does this end cap improve imaging with a Takahashi TOA-150 and the TOA67 flattener?

    When using a heavy camera on a system like the TOA-150 with its dedicated TOA67 flattener, standard thumbscrew-based adapters can allow for tiny amounts of tilt. This end cap creates a solid, threaded M92x1 connection, ensuring the flattener and camera are held perfectly square to the optical axis. This results in sharper stars across the entire large image circle the optics are designed to produce.

    Why is a threaded M92x1 connection better than a 2-inch compression ring?

    A threaded connection offers superior rigidity and reliability. While a compression ring is convenient, it can introduce microscopic tilt if not perfectly centered or if the payload is heavy. A threaded M92x1 connection physically locks the components together, providing a stable, repeatable, and flex-free foundation for your imaging system.

    Will this Starlight Instruments end cap work with an FSQ-106ED or its reducer?

    No, this end cap is not designed for the FSQ series telescopes or their reducers. It is specifically machined with an M92x1 male thread to match the Takahashi TOA645 and TOA67 large field flatteners. Always match the adapter thread to your specific corrector.

    Is this end cap difficult to install on a 3.5" Feather Touch focuser?

    Installation is straightforward. The end cap simply threads onto the end of the 3.5" Feather Touch focuser's drawtube in place of the original end cap. No special tools are required.

  • Focuser Compatibility Starlight Instruments 3.5" Feather Touch Focusers
    Accessory Thread M92x1 Male
    Flattener Compatibility Takahashi TOA645 / TOA67
    Material Aluminum
  • Starlight Instruments 2-Year Warranty