ZWO EFW-5×2-25 Electronic Filter Wheel

Description

Automated filter changes for efficient astrophotography

The ZWO EFW-5×2-25 Electronic Filter Wheel is designed to simplify and automate monochrome astrophotography workflows. By accommodating five 2-inch mounted filters, it allows users to switch between LRGB, narrowband, and specialty filters without manually intervening during an imaging session. This latest-generation model introduces several refinements focused on improving reliability, minimizing stray light, and providing a more seamless integration into modern astrophotography systems. Whether you're running a fully automated observatory or imaging from your backyard with an ASIAIR setup, the EFW-5×2-25 helps create a smoother and more efficient workflow.

Improved protection against stray light

Long-exposure deep-sky imaging is extremely sensitive to unwanted light entering the optical train. Even minor light leaks can introduce gradients and reduce image quality. To address this, ZWO redesigned the EFW with several structural improvements:

• A tighter-fitting chassis that minimizes potential entry points for stray light.
• Additional light-blocking pads at key connection points.
• A fully enclosed motor compartment for improved light isolation and environmental protection.

These improvements help produce cleaner calibration frames and more uniform long-exposure images.

Reliable operation during unattended imaging sessions

At the heart of the EFW-5×2-25 is a high-precision stepper motor that provides accurate positioning every time a filter change is required. The filter wheel supports bidirectional rotation, allowing it to choose the shortest path between filters, reducing movement time and improving efficiency during imaging sequences. When paired with ASIAIR, users can schedule complete imaging sessions that automatically switch filters without manual intervention. This makes unattended overnight imaging practical and reliable.

Lightweight yet durable construction

The EFW body is manufactured from CNC-machined aluminum alloy, providing excellent rigidity while keeping the overall weight low. Internally, the filter carousel uses 6061 aluminum alloy, a material chosen for its balance of strength, stability, and low mass. The result is a robust accessory built for repeated use in demanding astrophotography environments.

Modern USB-C connectivity

The new generation replaces the previous USB Type-B connector with a modern USB-C interface. The filter wheel draws only 120 mA at 5 V, allowing it to operate entirely through a single USB connection without requiring an external power supply. The package includes a USB 2.0 Type-A to USB-C cable, enabling quick and straightforward integration into your imaging setup. Its true plug-and-play design means no driver installation is necessary.

Broad software support

The EFW-5×2-25 integrates seamlessly with the ZWO ecosystem and supports multiple software platforms, including:

• ASIAIR
• ASIStudio
• ASCOM
• ZWO SDK

This broad compatibility makes it easy to incorporate into both simple and advanced astrophotography systems.

Who is this product for?

The ZWO EFW-5×2-25 is ideal for:

• Astrophotographers using monochrome astronomy cameras.
• Users building automated deep-sky imaging setups.
• Imaging systems using multiple LRGB and narrowband filters.
• ASIAIR users seeking unattended overnight imaging.
• Intermediate and advanced users looking to streamline their workflow.

What's in the box