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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 T2-1.25" Filter Adapter

ZWO T2-1.25" Filter Adapter

by ZWO
SKU ZWO-T2-1.25-3
$16.00 - $16.00
$16.00
$16.00 - $16.00
$16.00
Price Match Policy!
  • Connects M42 (T2) threaded cameras to 1.25" filters
  • Adds only 1 mm of optical length to the imaging train
  • Maintains critical back focus for correctors and reducers
  • Secure threaded connection prevents tilt and flexure
  • Lightweight, black-anodized aluminum construction
10 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • ZWO T2 to 1.25" Filter Adapter

    The ZWO T2 to 1.25" Filter Adapter adds standard 1.25" filter capability to any M42 T-threaded camera using just 1 mm of back focus. This low-profile solution is the most direct way to mount a single 1.25" filter for planetary imaging or guiding without the bulk of a filter wheel.

    Minimal Optical Path: Just 1 mm

    Consuming only 1 mm of your available back focus, this adapter is essential for complex imaging trains. When using a focal reducer or field flattener that demands precise sensor spacing, adding a filter without this adapter can be impossible. Its ultra-thin design allows you to add a UV/IR cut, narrowband, or LRGB filter without having to reconfigure your entire optical setup.

    Secure M42 Connection for 1.25" Filters

    A threaded connection is superior to slip-fit nosepieces for mounting filters. The adapter's M42 threads screw directly onto your camera body, creating a rigid, flex-free junction that prevents optical tilt. This ensures your sensor and filter remain perfectly parallel to the light path, a critical factor for maintaining a flat field and sharp stars corner-to-corner.

  • How does the ZWO T2-1.25" Adapter affect my back focus?

    The adapter adds exactly 1 mm of mechanical length to your imaging train. This is a minimal distance designed to preserve the critical back focus required by most optical correctors like field flatteners or coma correctors.

    Will this ZWO adapter work with non-ZWO cameras and filters?

    Yes. The adapter uses the universal M42 (T2) thread standard on the camera side and accepts any standard 1.25" astronomy filter. It is compatible with any T-threaded astronomy camera and any brand of 1.25" filter.

    Can I use the ZWO T2-1.25" Adapter with a filter wheel?

    No, this adapter is designed as an alternative to a filter wheel for single-filter applications. It threads directly into the camera body where a filter wheel would normally attach. It is ideal for monochrome guide cameras or for color cameras where you only need to add a single light pollution or UV/IR cut filter.

    What is the advantage of this adapter over a 1.25" nosepiece with filter threads?

    The primary advantage is rigidity. A direct M42 thread connection prevents the tilt and sag that can occur with a nosepiece held in place by thumbscrews. This secure, parallel connection is crucial for avoiding image degradation, especially with sensitive optical systems.

    Is the ZWO T2-1.25" Adapter a good choice for adding a UV/IR cut filter to my ASI178MC for lunar imaging?

    Absolutely. For planetary, lunar, or solar imaging with a one-shot-color camera like the ASI178MC, adding a single UV/IR cut filter is critical for sharp focus. This 1 mm adapter provides the most secure and lowest-profile method to do so without altering your setup significantly.

    How do I tighten the ZWO T2-1.25" Adapter?

    The adapter has four small holes on its face. While it can often be tightened by hand, if you need extra leverage, you can use a spanner wrench or the tips of a small pair of needle-nose pliers inserted into two opposing holes to gently secure it to your camera body.

  • SKU ZWO-T2-1.25-3
    Camera Side Connector M42 (T2) Female Thread
    Filter Side Connector 1.25" Female Thread
    Optical Length 1 mm
    Warranty 2 Years

    • T2 to 1.25" Filter Adapter

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  • ZWO 2-Year Manufacturer Warranty