Skip to content
July 1st: Store will be closed for Canada Day. Orders placed that day will ship on July 2nd.
July 1st: Store will be closed for Canada Day. Orders placed that day will ship on July 2nd.
ZWO T2-1.25" Filter Adapter

ZWO T2-1.25" Filter Adapter

by ZWO
SKU ZWO-T2-1.25-3
CA$22.00 - CA$22.00
CA$22.00
CA$22.00 - CA$22.00
CA$22.00
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
1 in stock
Qualifies for FREE Shipping in Canada on orders over $500.
  • 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

      × 1

  • ZWO 2-Year Manufacturer Warranty