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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.
ZWO M48-M42 Adapter

ZWO M48-M42 Adapter

by ZWO
SKU ZWO-M48-M42
$12.00 - $12.00
$12.00
$12.00 - $12.00
$12.00
Price Match Policy!
  • Converts female M48x0.75 threads to female M42x0.75 T-threads
  • Adds only 4 mm of optical path length to the imaging train
  • Standard accessory for many ZWO Pro series cameras
  • Durable black anodized aluminum construction
4 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • ZWO M48 to M42 Adapter

    The ZWO M48 to M42 Adapter is the essential component for connecting accessories with different thread standards, converting the wider M48 (2-inch filter) thread to the universal M42 T-thread. This simple ring uses only 4 mm of back focus, making it a compact solution for integrating filter wheels, flatteners, and cameras into a single, secure optical train.

    A 4 mm Solution for Thread Incompatibility

    This adapter solves one of the most common connection problems in astrophotography. It allows you to attach a male M48-threaded accessory, like the output of a 2-inch filter wheel or field flattener, directly to a component that requires a male M42 T-thread, such as an off-axis guider or camera body. The adapter itself has female threads on both sides, acting as a converter ring that occupies a minimal 4 mm of optical distance.

    Designed for ZWO Pro Camera Systems

    While universally useful, this M48-M42 adapter is the same unit included with many ZWO cooled cameras. It's specifically designed to work with other ZWO accessories like the 16.5mm extender or an Off-Axis Guider (OAG). When used in these specific configurations, it provides the correct thread type without altering the designed total back focus of the system, ensuring you can reach the required 55 mm spacing without complex calculations.

  • What is the primary use for the ZWO M48-M42 Adapter?

    Its primary function is to convert the larger M48x0.75 female thread, commonly found on 2-inch filter holders and field flatteners, into the smaller M42x0.75 female T-thread used by most astronomy cameras, T-rings, and off-axis guiders. This allows you to connect components that would otherwise be incompatible.

    How much back focus does the ZWO M48-M42 Adapter use?

    The adapter itself has an optical path length of 4 mm. This distance must be factored into your total back focus calculation when adding it to your imaging train.

    Is this the same adapter that comes with ZWO cameras?

    Yes, this is the same stock M48-M42 adapter ring that is included with many ZWO Pro series cameras. It is offered here as a replacement part or for users who need to adapt other non-ZWO hardware.

    Can I use the ZWO M48-M42 Adapter to connect a 2" filter wheel to my camera's T-ring?

    Yes, this is a perfect application. If your 2" filter wheel has a male M48 thread on the camera side, and your camera's T-ring has a male M42 thread, this adapter will bridge the two components securely, consuming only 4 mm of your available back focus.

    Will this ZWO adapter cause vignetting on my full-frame camera?

    Because this adapter steps down from the larger M48 format to the smaller M42 T-thread, it can introduce vignetting on full-frame (24x36mm) sensors, especially in fast optical systems (f/5 or lower). The M42 thread has a smaller clear aperture than M48, which can clip the light cone before it reaches the corners of a large sensor.

    What are the threads on the ZWO M48-M42 Adapter?

    The adapter has female threads on both sides. One side is an M48x0.75 thread, and the other side is an M42x0.75 T-thread.

  • SKU ZWO-M48-M42
    Thread Conversion M48x0.75 (Female) to M42x0.75 (Female)
    Optical Length 4 mm
    Warranty 2 Years

    • ZWO M48 to M42 Adapter Ring

      × 1

  • ZWO 2-Year Limited Warranty