ZWO EFW Electronic Filter Wheel — 5 × 1.25-inch

ZWO EFW Electronic Filter Wheel — 5 × 1.25-inch

The ZWO EFW 5 × 1.25-inch is a motorised 5-position electronic filter wheel for automated filter changes during imaging. This entry uses the current USB-C EFW generation and its model-specific dimensions.

Filters and optical spacing

Supported filters: 1.25-inch mounted (M28.5 × 0.6; filter area ≤7 mm); 31 mm unmounted, 1.5–3.5 mm thick. The effective optical-path occupancy is 20 mm; the external casing dimensions of 129 × 120 × 30 mm include the full mechanical housing. Net weight is 300 g.

Drive and light sealing

A high-precision stepper motor provides bidirectional indexed rotation. The CNC-machined aluminium housing, 6061 aluminium carousel, slot-fit covers, connection pads and enclosed motor compartment are designed to reduce stray-light entry.

Power and software

One USB 2.0 Type-C connection supplies 5 V power and control; ZWO lists 120 mA consumption, with no separate power adapter required. The wheel supports ASIAIR, ASIStudio, ASCOM and the ZWO SDK.

Installation

Use the exact model manual for filter retaining screws, camera-side connections and thickness clearances. For third-party mounted filters, ZWO recommends standard 2.5 mm cells and gives additional restrictions for cells wider than the wheel counterbore. Keep all filter fasteners below the specified clearance to prevent carousel obstruction.

ZWO manufacturer documentation

Compatibility notes

Use the exact named-model manufacturer connection and operating instructions linked with this product. Optional parts and adapters require their specified spacing and power limits.

Additional specifications