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ZWO

ZWO EFWmini

ZWO EFWmini

SKU:EFW mini

Regular price £182.00
Regular price Sale price £182.00
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ZWO EFWmini (5 x 1.25″or 5 x 31mm)

Discover the Latest in Astro Photography: ZWO's Ultra-Compact 5-Position Filter Wheel

ZWO is proud to introduce one of the world's tiniest 5-position electronic filter wheels, setting new standards in the astro photography equipment landscape. This marvel of engineering is not only compact but also incredibly light, tipping the scales at a mere 300 grams.

Crafted from the highest quality aircraft-grade aluminium alloy, the filter wheel's housing undergoes precision CNC machining to ensure durability and performance. At its core lies a stepper motor manufactured by the esteemed Japanese company, NPM, known for its exceptional quality and reliability. This crucial component guarantees smooth and precise filter transitions, making it an indispensable tool for serious astro photographers.

Designed with astro photography enthusiasts in mind, this filter wheel is optimized for use with ZWO ASI1600 cameras, though its compatibility extends far beyond, thanks to its ASCOM support. This allows for seamless integration with various camera models, enhancing its versatility.

The filter wheel accommodates up to five filters in its numbered compartments, compatible with standard 1.25" filter threads. Alternatively, it can hold 31mm unmounted or semi-mounted Astronomik filters, each selectable via imaging software for optimal viewing or imaging. While ZWO currently offers 1.25" filters, plans to introduce 31mm options are underway, promising even greater flexibility.

Installation is a breeze, thanks to the included 1.25” nosepiece adaptor or T-thread options, with a female T-thread present on both sides for added convenience. For those who prefer unfiltered viewing, one compartment can remain empty.

ZWO's commitment to quality is further evident in the filter wheel's construction, supplied with a 1.25” nosepiece and an eyepiece holder featuring a brass compression ring for secure fitting.

Please note, the addition of the filter wheel necessitates 20mm of extra inward focusing distance from your standard focus position, a small adjustment for a significant upgrade in imaging capability.

This filter wheel is an excellent companion for the ASI1600 camera series, particularly the monochrome variants. However, it's essential to ensure your telescope system has sufficient back focus capacity, especially for Newtonian telescopes, which may require modifications for optimal use.

With an optimal distance of 10-12mm between the filter and sensor when paired with the ASI1600, the filter wheel supports up to f/7 - f/8 focal ratios for 1.25" filters and up to f/2 for 31mm filters, minimizing vignetting. ZWO's new RGBL filters are recommended for the ASI1600, designed to achieve a nearly perfect 1:1:1 RGB color balance.

The full ZWO EFWmini set includes everything needed for immediate setup: the EFWmini Body, T2 nosepiece, 1.25″ Holder-T2, T2-T2 adapter, USB2.0 Cable, and the necessary screws and washers for 31mm filters. Specifications highlight the device's efficiency and compatibility, featuring a low power consumption of 150 mA at 5 volts, accommodating 5 x 1.25" or 5 x 31mm filters, and boasting a lightweight design at 300g.

Embrace the future of astro photography with ZWO's cutting-edge electronic filter wheel, designed for precision, versatility, and ease of use.

The body is CNC machined from a full block of aircraft-grade aluminum.

Very thin design, 20mm ONLY

The step motor is the heart of the EFWmini, which is made by NPM from Japan. You can trust its quality and reliability.

Supports both 5*1.25″ filters or 5*31mm filters

The Electronic Filter wheel can be rotated in both counterclockwise or clockwise direction for filter selection.

Only one USB Cable is enough to power up the EFW, the max power consumption is around 120ma@5V, so you can connect it from the USB 2.0 hub of our cooled cameras.


The distance between the filter and sensor is around 10mm when you connect it to ASI1600.

So 1.25″ filters won’t have vignetting up to F5 focal ratio scope and 31mm filters won’t have vigentting up to F2 lens

Our new RGBL filters are recommended to work with ASI1600, it will offer nearly 1:1:1 RGB color balance.

What’s in the box?

  1. EFWmini body
  2. 1.25″ cover
  3. T2 nosepiece
  4. 1.25″ holder(with cover and 2 screws)
  5. T2-T2 adapter(male)
  6. A bag of filter masks
  7. USB2.0 2m cable
  8. Phillips screwdriver
  9. A bag of M2 screws

Mechanical drawing

How to use it?

you just need to plugin the EFW mini with USB2.0 cable and install the   ASCOM driver

There are  ZWO Filter Wheel(1) and ZWO Filter Wheel(2) to select,  you can use either one of them

There are 2 ASCOM for controlling 2 EFWmini in one software.

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