ZWO EFW 7x2" Electronic Filter Wheel

Description

ZWO Precision Motorized Filter Wheel for Astrophotography

The ZWO EFW 2" Electronic Filter Wheel is a premium accessory designed to make filter changes during astrophotography smooth, fast, and reliable. It is built from a solid block of aircraft-grade aluminum, with the body which combines strength with a slim profile of just 20mm thickness, making it one of the thinnest and lightest filter wheels available for astrophotographers.

The filter wheel is available in two versions: the ZWO EFW 5x2" with 5-position, and the EFW 7x2" (current version) with 7-position, weighting 0.5 kg and 0.65 kg respectively, giving you flexibility depending on your imaging needs. Both versions support either 2" thread-in filters or 50.4mm unmounted filters, with the option to rotate filters in both clockwise and counter-clockwise directions for quick and precise selection.

At the core of the wheel is a high-precision stepper motor from NPM, Japan, ensuring smooth, accurate, and reliable movement even during long exposure sessions. The ZWO EFW 7x2" is also extremely easy to power and control: a single USB 2.0 connection handles both, drawing only about 120mAh @ 5V—which means it can even run directly from the USB port of a cooled ZWO camera.

Compatibility

For astrophotographers using the ZWO ASI6200MM Pro, the filter-to-sensor distance is about 18mm, reducing vignetting and ensuring sharp image quality. ZWO also recommends pairing this wheel with their 2" LRGB filters, designed to provide nearly 1:1:1 RGB color balance when imaging.

When using third-party filters, please note the following requirements:

• Filter thickness (excluding threads) must be less than 7.5mm
• Filter diameter must not exceed 50.8mm
• Thread thickness should be under 2.7mm

What’s in the box?

The ZWO EFW 7x2" comes complete with everything you need to integrate it into your imaging setup:

1. Electronic Filter wheel body (ZWO EFW 7x2")
2. USB 2.0 cable (2m)
3. M2.5*6 screws (6 pcs)
4. Filter masks for 50mm filters (7 pcs)
5. Phillips screwdriver
6. M2*4 flat screws (23 pcs)
7. M54M–M48F adapter
8. M54M–M42F adapter
9. Darkening ring set (4 pcs) – designed to eliminate light leaks between the filter wheel and camera

Darkening Ring Specifications

• External diameter: 88mm
• Inner diameters: 55mm (2 pcs) and 58mm (2 pcs)
• Thickness: ≤0.2mm

With its precision engineering, robust build, and ease of use, the ZWO EFW 2" is the ideal electronic filter wheel for serious astrophotographers who demand performance and reliability in every imaging session.