ZWO FF131 APO Flat-Field Apochromatic Refractor

The ZWO FF131 APO is a premium flat-field apochromatic refractor designed for advanced astrophotography and visual observation. Featuring a four-element optical design, full-frame sensor support, and native flat-field performance, it delivers exceptional image quality with simplified setup.

Native Flat-Field Optical Design

The FF131 APO features a four-element fully air-spaced apochromatic optical system that produces a naturally flat imaging field without requiring an additional field flattener.

ED Glass for Superior Colour Correction

An extra-low dispersion (ED) glass element effectively reduces chromatic aberration, resulting in improved colour accuracy, higher contrast, and sharper images.

44mm Image Circle for Full-Frame Cameras

Designed to support full-frame astronomy cameras, the FF131 APO provides excellent edge-to-edge sharpness and consistent image quality across the entire imaging field.

Simplified Astrophotography Setup

The native flat-field design eliminates the need for additional field flatteners and complicated spacing calculations, making setup faster and more convenient.

Precision Dual-Speed Focuser

A rigid 3-inch rack-and-pinion focuser features a 1:10 fine-focus adjustment mechanism for precise focusing. The integrated 360° rotator allows smooth and accurate camera framing.

Retractable Dew Shield

The retractable dew shield improves portability while helping minimise stray light and dew formation during observing and imaging sessions.

Flexible Imaging Connectivity

The included four-section photographic extension tube features a 2-inch filter thread and includes M48×0.75 and M54×0.75 adapters for compatibility with a wide range of astrophotography accessories.

Quick-Release Mounting Rings

Detachable mounting rings allow for fast installation, easy transport, and convenient storage.

Ideal For

Full-frame astrophotography, deep-sky imaging, advanced imaging systems, visual astronomy, and observatory or portable telescope setups.