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Pegasus Astro Adapter M48 male to M42 female

Pegasus Astro Adapter M48 male to M42 female

by Pegasus Astro
SKU PEG-ADAPT-M48M-M42F
$24.00 - $24.00
$24.00
$24.00 - $24.00
$24.00
Price Match Policy!
  • Connects M48 (2-inch filter) accessories to M42 (T-thread) components
  • Adds only 2mm of optical path length
  • Standard 0.75mm thread pitch for universal compatibility
  • Male M48x0.75 thread with 4mm length
  • Female M42x0.75 T-thread
2 in stock
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Check which filter and adapter sizes clear the sensor with the Pegasus Astro Adapter M48 male to M42 female, and how much light the corners lose.

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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Adapter M48 male to M42 female

    This M48 Male to M42 Female Adapter solves a critical connection problem with a minimal optical profile of just 2mm. It features a standard 0.75mm thread pitch and a 4mm male thread length, ensuring a secure fit between larger M48 format correctors and smaller M42 T-thread accessories like cameras or filter wheels.

    Bridge Your M48 Corrector to M42 Accessories with a 2mm Profile

    This adapter is the essential component for connecting an imaging train that uses mixed thread sizes. It allows you to attach M42 T-thread cameras, off-axis guiders, or filter wheels directly to a coma corrector or field flattener that terminates in a male M48x0.75 thread. By adding only 2mm to the total optical path, it helps you maintain the critical back focus distance required by your corrector, a major challenge when integrating multiple accessories.

    The male M48 thread has a 4mm length, providing robust engagement with the female threads on your corrector for a rigid, no-tilt connection. The internal M42x0.75 female T-thread is the universal standard for most dedicated astronomy cameras, ensuring broad compatibility across your existing equipment.

  • When do I need this M48 to M42 adapter?

    You need this adapter when your field flattener or coma corrector has male M48 threads (often called "wide T-mount"), but your next accessory in the imaging train, such as a filter wheel or the camera itself, has female M42 T-threads. This adapter steps down the thread size while consuming a minimal 2mm of back focus.

    Will this adapter work with my 2-inch filters?

    No, this is not a filter cell. This adapter is designed to change the thread standard of your imaging train from M48 to M42. While M48 is the same thread as 2-inch filters, this adapter's purpose is mechanical connection, not filter placement.

    Why is the 2mm length of this M48 to M42 adapter important?

    Most correctors require a precise back focus distance (typically 55mm) from the corrector's flange to the camera sensor. Every adapter consumes some of this distance. At only 2mm thick, this adapter uses a very small amount of your available back focus, leaving more room for other critical components like off-axis guiders or filter wheels.

    Can I use this adapter to connect my ZWO ASI camera to a Sky-Watcher Quattro coma corrector?

    Yes, this is a perfect use case. The Sky-Watcher Quattro coma corrector typically outputs an M48 male thread. This adapter will convert that to the M42 female thread needed to connect ZWO's standard M42-threaded extension tubes or the camera body itself, helping you achieve the correct spacing.

    Is the M48 to M42 adapter strong enough to hold a heavy camera?

    Absolutely. The adapter is machined from metal and designed to be a rigid part of the optical train. The 4mm male thread length ensures a secure, load-bearing connection that will not flex or tilt under the weight of a typical cooled astronomy camera and filter wheel.

    Will this adapter cause vignetting with my full-frame sensor?

    Stepping down from a wider M48 opening to a smaller M42 T-thread can introduce vignetting on sensors larger than APS-C format, especially in fast optical systems. While the adapter itself is low profile, the M42 thread standard (with a ~41mm clear aperture) is the limiting factor and is generally not recommended for full-frame (36mm x 24mm) sensors.

  • Total Optical Length 2mm
    Male Thread M48x0.75
    Female Thread M42x0.75
    Male Thread Length 4mm

    • Adapter M48 male to M42 female

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  • Pegasus Astro 2-Year Warranty