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ZWO Filter Drawer V2 - M42
ZWO Filter Drawer V2 - M42
ZWO Filter Drawer V2 - M42
ZWO Filter Drawer V2 - M42
ZWO Filter Drawer V2 - M42

ZWO Filter Drawer V2 - M42

by ZWO
SKU ZWO-FD-M42-II
$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00
Price Match Policy!
  • Accepts standard 2-inch mounted filters
  • Adds a precise 21mm to the optical path
  • M42 x 0.75 male threads on the camera side
  • M48 x 0.75 female threads on the telescope side
  • Magnetic holder secured by a mechanical lock screw
47 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • ZWO Gen 2 M42 x 0.75 Filter Drawer for 2" Filters

    The ZWO Gen 2 M42 x 0.75 Filter Drawer for 2" Filters integrates into your imaging train with a precise 21mm optical thickness, a critical value for achieving correct back focus with most correctors. It connects to your camera via M42 x 0.75 threads and to your telescope with M48 x 0.75 threads, and includes an M42-M48 adapter ring for additional hardware compatibility. This second-generation design holds any standard 2-inch filter securely, using strong magnets and a mechanical locking screw to eliminate filter shift and light leaks during long exposures.

    Zero-Flexure Holder for 2-Inch Filters

    For long-exposure astrophotography, any movement or light leak in the optical path can degrade the final image. The Gen 2 drawer addresses this by using powerful magnets to seat the filter holder, which is then secured with a dedicated locking screw. This two-point system ensures the 2-inch filter remains perfectly orthogonal to the light path, preventing tilt and ensuring your flat frames remain valid even after slewing across the sky.

    21mm Optical Path with M42 & M48 Threads

    Achieving the standard 55mm back focus distance is simplified with this filter drawer's 21mm total optical thickness. The body features M48x0.75 female threads on the telescope side for direct connection to most coma correctors and field flatteners. On the camera side, M42x0.75 male threads provide a secure link to ZWO's lineup of APS-C and smaller cameras. An included M48-M42 adapter ring converts an M48 female thread to M42 female for connecting M42-threaded accessories.

    Gen 2 vs. Gen 1: A Critical Compatibility Note

    This Gen 2 Filter Drawer is a complete redesign focused on light leak prevention and mechanical stability. As a result, the physical dimensions of the filter holder have changed. Spare filter holders purchased for the first-generation (Gen 1) ZWO M42 filter drawer are not compatible with this Gen 2 housing, and vice-versa. This drawer is a self-contained system and should not be mixed with first-generation components.

  • What size filters does the ZWO M42 Filter Drawer V2 accept?

    The ZWO M42 Filter Drawer V2 is designed to hold standard 2-inch mounted filters. The internal filter holder has M48x0.75 female threads to accept the male threads on the filter cell.

    Is the Gen 2 ZWO M42 Filter Drawer compatible with filter holders from the first generation?

    No. This is a critical point of incompatibility. The Gen 2 filter drawer and its holders have been redesigned and are not physically compatible with the holders from the first-generation (Gen 1) ZWO filter drawer. You must use Gen 2 holders with this Gen 2 drawer.

    How does the ZWO M42 Filter Drawer V2 fit into an imaging train requiring 55mm of back focus?

    The filter drawer has an optical thickness of 21mm. On a ZWO camera with 17.5mm of back focus, the camera and drawer together give 38.5mm, so 16.5mm is still needed to reach 55mm (17.5mm + 21mm + 16.5mm = 55mm). Thread the 16.5mm M48 extender that comes with your ZWO cooled camera onto the telescope side of the drawer. If your imaging train uses an off-axis guider, the ZWO OAG goes in that position instead of the 16.5mm extender.

    What are the thread sizes on the ZWO M42 Filter Drawer V2?

    The filter drawer has two primary connection threads:

    • Telescope Side: M48x0.75 female threads.
    • Camera Side: M42x0.75 male threads (T-threads).
    • It also includes an M48-M42 adapter (M48 to M42 female) for additional configurations.

    When imaging the Andromeda Galaxy (M31) with a color camera, how does the ZWO M42 Filter Drawer V2 help?

    The ZWO M42 Filter Drawer V2 allows you to quickly swap between different 2-inch filters without unthreading your camera. For a target like the Andromeda Galaxy (M31), you could capture the core and spiral arms with a broadband light pollution filter (like an L-Pro), then quickly slide in a dual-band filter (like an L-eNhance or L-eXtreme) to gather H-alpha data from the star-forming regions, all within the same imaging session.

    How does the locking mechanism on the ZWO M42 Filter Drawer V2 prevent imaging problems?

    The system uses both magnets for initial seating and a manual lock screw for final security. This prevents the filter from shifting as the telescope slews, which can cause optical tilt and ruin guiding or image sharpness. The tight seal created by this system also blocks stray light, which is essential for eliminating gradients and reflections during long exposures.

  • SKU ZWO-FD-M42-II
    Accessory Type Filter Drawer
    Filter Compatibility 2" Mounted Filters (M48x0.75 threads)
    Optical Thickness 21 mm
    Telescope Side Threads M48 x 0.75 Female
    Camera Side Threads M42 x 0.75 Male
    Warranty 2 Years

    • Gen 2 M42 Filter Drawer Body

      × 1

    • Gen 2 Filter Holder for 2" Filters

      × 1

    • M42-M48 Adapter Plate

      × 1

  • ZWO 2-Year Limited Warranty