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Starlight Instruments 1.25" Adapter for Astro-Tech 6", 8" and GSO 6", 8" RC Telescope

by Starlight Instruments
SKU SI-A15-1503-2
CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00
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  • Mounts a 1.25" Feather Touch focuser (FTF1575BCR or FTF1575BCR-DS)
  • Fits Astro-Tech & GSO 6" and 8" RC telescopes, newer WO Megrez 80/90mm and GT81
  • Features a secure 90x1mm female thread
  • Precision-machined by Starlight Instruments for a zero-flexure fit
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Starlight Instruments 1.25" Adapter for Astro-Tech & GSO RC Telescopes

    The Starlight Instruments 1.25" Adapter provides a direct, threaded connection for a Starlight Instruments 1.25" Feather Touch focuser (FTF1575BCR or FTF1575BCR-DS) on Astro-Tech and GSO 6" and 8" Ritchey-Chrétien telescopes. It features a female 90x1mm thread for attachment to these telescopes in place of the stock focuser.

    Threaded Mount for the 1.25" Feather Touch Focuser

    This Starlight Instruments adapter takes the place of the stock focuser and threads onto the telescope's M90x1 thread, giving a 1.25" Feather Touch focuser (FTF1575BCR or FTF1575BCR-DS) a direct, threaded connection to the telescope. Your eyepieces or camera then attach to that focuser.

  • What is the thread size on the Starlight Instruments 1.25" Adapter for Astro-Tech RCs?

    This adapter features a 90x1mm female thread on the telescope side, designed to attach to the corresponding male thread on compatible telescopes where the stock focuser was fitted.

    Which telescopes is this Starlight Instruments 1.25" adapter compatible with?

    It is known to fit Astro-Tech and GSO 6" and 8" Ritchey-Chrétien telescopes, the newer William Optics Megrez 80/90mm and the William Optics GT81. Verify that your telescope has an M90x1 thread where the stock focuser attaches before purchasing.

    Can I use this Starlight Instruments adapter for visual observing on my GSO 8" RC?

    Yes, absolutely. This adapter's purpose is to mount a 1.25" Feather Touch focuser (FTF1575BCR or FTF1575BCR-DS) on your 8" GSO RC; your 1.25" eyepieces then go in that focuser. It provides the secure, threaded connection needed for a stable and sharp view.

    Will this adapter let me reach focus with my eyepieces on an Astro-Tech 6" RC?

    This adapter provides the correct mechanical connection. Achieving focus with your Astro-Tech 6" RC will still depend on the telescope's back focus and your specific eyepiece. Ritchey-Chrétien telescopes often require using a specific combination of extension tubes to place the eyepiece at the focal plane, and you may need to add or remove extenders to suit your setup.

    How does the Starlight Instruments adapter hold a 1.25" eyepiece in place?

    It does not hold eyepieces directly: the adapter mounts a Starlight Instruments FTF1575BCR or FTF1575BCR-DS Feather Touch focuser, and the eyepiece is held in that focuser. Starlight Instruments components are machined to tight tolerances for a precise, non-slip fit.

  • Accessory Compatibility Starlight Instruments FTF1575BCR / FTF1575BCR-DS 1.25" Feather Touch focuser
    Telescope-Side Connection 90x1mm Female Thread
    Telescope Compatibility Astro-Tech 6" & 8" RC, GSO 6" & 8" RC, William Optics newer Megrez 80/90mm, William Optics GT81
    Kind Tube adapter
    Focuser Starlight Instruments FTF1575BCR / FTF1575BCR-DS 1.25" Feather Touch

    • 1.25" Adapter for Astro-Tech/GSO RC Telescopes

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  • Starlight Instruments 2-Year Warranty