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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.
Baader Expanding Ring - T-2(F)/M48x0.75(M)
Baader Expanding Ring - T-2(F)/M48x0.75(M)

Baader Expanding Ring - T-2(F)/M48x0.75(M)

by Baader Planetarium
SKU BAA-2458110
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Price Match Policy!
  • Converts female T-2 (M42x0.75) threads to male M48x0.75 threads
  • Functions as a T-2 to 2-inch filter thread adapter
  • Enables connection of T-2 accessories to larger format correctors
  • Machined for a secure, non-flexing connection
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  • Description
  • FAQ
  • Specifications
  • In the Box
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  • Warranty

  • Baader Expanding Ring - T-2(F)/M48x0.75(M)

    The Baader T-2 to M48 Expanding Ring adapts the universal female T-2 (M42x0.75) thread to the larger male M48x0.75 standard, creating a secure, full-aperture connection to 2-inch accessories. This single adapter is a fundamental component for any astrophotographer looking to connect a T-2 threaded camera to a modern field flattener, reducer, or 2-inch filter wheel that uses M48 threads.

    Bridge Your T-2 and M48 Imaging Train

    In many imaging setups, the camera or off-axis guider uses the M42-based T-2 thread standard, while larger format correctors and filter wheels have adopted the M48 thread to prevent vignetting on larger sensors. This expanding ring acts as the crucial bridge, allowing you to step up the thread size early in the imaging train to maintain the widest possible light cone.

    • Eliminate Bottlenecks: By converting from T-2 to M48, you ensure your optical train is not restricted by the smaller M42 diameter, which is especially important for full-frame or large APS-C sensors.
    • Connect to 2" Filters: Attach your T-2 camera directly to a 2-inch filter wheel or filter slider that features a male M48 thread on the telescope side.
    • Universal Compatibility: Baader's precise machining ensures a perfect fit with accessories from any manufacturer that adheres to the T-2 and M48 thread standards.

  • What is the primary purpose of the Baader T-2 to M48 Expanding Ring?

    Its main purpose is to convert the smaller female T-2 (M42x0.75) thread found on many astronomy cameras and accessories into a larger male M48x0.75 thread. This allows you to connect T-2 devices to components like 2-inch filter wheels, coma correctors, and field flatteners that use the M48 standard.

    Will this Baader adapter add significant length to my imaging train?

    While any adapter adds some optical path length, expanding rings like this are designed to be as thin as possible. Baader Planetarium engineers these components to contribute minimal back focus, ensuring you can reach focus and maintain the correct spacing for your optical correctors.

    Can I use the Baader T-2/M48 ring to attach a ZWO camera to a 2" filter wheel?

    Yes, absolutely. Most ZWO cameras feature a female T-2 thread when their 1.25" nosepiece is removed. This adapter will thread directly onto the camera body, presenting a male M48 thread that can connect to the telescope-side of most 2-inch filter wheels.

    Does this adapter have threads for 1.25" filters?

    No. This is strictly a thread converter. It does not have internal threads for mounting filters. Its purpose is to allow connection to accessories that hold 2-inch (M48) filters.

    Why would I expand to M48 instead of staying with T-2 threads for my full-frame camera?

    Using T-2 (M42) threads with a full-frame sensor can cause significant vignetting, where the corners of the image are darkened because the light path is physically constricted. Stepping up to the larger M48 diameter as close to the sensor as possible provides a wider, un-obstructed opening for the light cone, resulting in more even illumination across the entire frame.

    Is the male M48 thread on this Baader adapter long enough to attach multiple accessories?

    The male M48 thread is a standard length designed to make a secure connection with one female-threaded accessory. It is not an extension tube and is not intended for stacking multiple components on its male thread.

  • Input Thread (Female) T-2 (M42x0.75)
    Output Thread (Male) M48x0.75
    Type Expanding Ring / Thread Adapter
    Net weight (kg) 0.01
    Inner Diameter / Clear Aperture (mm) 41
    Outer Diameter 50.5
    Optical length (mm) 2.5
    T-2 Part # 29
    Outer Connection (eyepiece/-camera-sided) M48
    Adapters Family T-2 System, M48 System

    • Baader Expanding Ring - T-2(F)/M48x0.75(M)

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  • Baader Planetarium Warranty