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Baader 1" C-Mount Adapter w/ 1.25" Nosepiece - 18mm Long

SKU BAA-2958515
Original price CA$57.00 - Original price CA$57.00
Original price
CA$57.00
CA$57.00 - CA$57.00
Current price CA$57.00
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  • Connects C-Mount (1") cameras to 1.25" focusers
  • Has an 18mm insertion length and adds 4mm of optical length
  • Internal threads accept standard 1.25" mounted filters
  • Includes retainer ring for unmounted filters (27.5mm - 28mm)
  • Durable, precision-machined Baader construction
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty
  • Baader 1" C-Mount Adapter w/ 1.25" Nosepiece - 18mm Long

    The Baader 1" C-Mount Adapter provides a secure, 18mm long connection between C-Mount cameras and standard 1.25" focusers or accessories. It features internal threads for standard 1.25" eyepiece filters and includes a retainer ring to mount unmounted filters between 27.5mm and 28mm in diameter.

    A Precise 18mm C-Mount to 1.25" Connection

    This adapter bridges the gap between the common C-Mount thread found on many guide, planetary, and video astronomy cameras and the universal 1.25" format. Its 18mm nosepiece slides into the focuser, so the adapter adds only 4mm of optical length, a critical factor when calculating the back focus for your imaging train. This specific length is often required to bring guide cameras to focus in off-axis guiders or to achieve the correct spacing for other accessories.

    Integrated 1.25" and 28mm Filter Compatibility

    A key feature of this Baader adapter is its built-in support for filters. The 1.25" nosepiece is threaded to accept standard mounted M28.5 filters, allowing you to easily add a UV/IR cut, narrowband, or color filter to your imaging setup. For more advanced applications, an included retainer ring allows for the secure installation of an unmounted filter with a diameter from 27.5mm to 28mm, saving precious back focus and reducing the optical length.

  • What is the primary use for the Baader 1" C-Mount Adapter?

    The Baader 1" C-Mount Adapter is designed to connect a camera with female C-Mount threads (a common standard for guide and planetary cameras) to a telescope's 1.25" focuser, an off-axis guider, or any other accessory that accepts a 1.25" nosepiece. It also adds 4mm of optical length (the nosepiece has an 18mm insertion length).

    Can I use the Baader 18mm C-Mount adapter with a ZWO ASI120MM Mini guide camera?

    Yes. The ZWO ASI120MM Mini and many similar guide cameras use a C-Mount thread. This adapter will allow you to insert the camera into a standard 1.25" guide port or focuser. The 18mm length is often helpful for achieving focus in various off-axis guider models.

    How do I install a filter with this Baader adapter?

    You have two options. For a standard 1.25" mounted filter, you simply screw it into the internal threads on the end of the 1.25" nosepiece. To use an unmounted filter (27.5mm - 28mm diameter), you place the filter inside the adapter and secure it with the included retainer ring.

    Why would I use an unmounted filter with the Baader C-Mount Adapter?

    Using an unmounted filter with the included retainer ring can save a few millimeters of back focus compared to threading a mounted filter onto the end. This can be critical in imaging trains with very tight spacing requirements. It's a specialized feature for optimizing your optical configuration.

    Will this Baader adapter work in a 2" focuser?

    Yes, but you will need a 2" to 1.25" adapter. This Baader adapter has a 1.25" nosepiece, so it will not fit directly into a 2" focuser. You must use the appropriate step-down adapter, which typically comes standard with most 2" focusers.

    How much spacing does this Baader adapter add for my C-Mount guider?

    It adds 4mm, not 18mm. The Baader 1" C-Mount Adapter w/ 1.25" Nosepiece has a fixed, non-adjustable 18mm insertion length and 4mm of optical length. It serves as both an adapter and a precision spacer.

  • Camera-Side Connection C-Mount (1" x 32 TPI), Male
    Telescope-Side Connection 1.25" Nosepiece
    Optical Length 4mm
    Filter Thread 1.25" (M28.5 x 0.6)
    Unmounted Filter Support Yes, 27.5mm - 28mm diameter via included retainer ring
    Net weight (kg) 0.01
    Compatible Brands Astro T-2, UNC, Baader Planetarium, Celestron, Other
    Inner Diameter / Clear Aperture (mm) 22
    Outer Diameter 34
    Type of Adapter Camera Adapter, Expanding Adapter, Filter holder
    Inner Connection (lens sided) M28.5
    Outer Connection (lens sided) ø 1¼" (31.75 mm)
    • 1" C-Mount Adapter w/ 1.25" Nosepiece (18mm)

      × 1

    • Retainer Ring for Unmounted Filters

      × 1

  • Baader Planetarium Warranty