Omegon SWA 20mm 70° 1.25″ eyepiece
The Omegon SWA super wide-angle eyepiece series represents a genuine breakthrough in affordable wide-field optics. The SWA 20mm with a 70° apparent field of view draws you into the observing experience so intensely that you will feel as though you are looking into space directly through a spaceship window - no distracting edges, no need to constantly shift your gaze. Star clusters, nebulae and planets finally get the space they deserve.
Optics and coatings
The eyepiece is built around a five-element optical system arranged in three or four groups. This configuration achieves excellent aberration correction while maintaining the wide 70° field of view. All optical surfaces are treated with broadband fully multi-coated (FMC) anti-reflection coatings, which maximise light transmission across the entire visible spectrum. The result is a bright, high-contrast and true-to-life image even when working with demanding deep-sky objects. The lens edges are blackened to effectively suppress internal light scatter and stray reflections that would otherwise reduce image contrast.
Construction and ergonomics
The eyepiece body has undergone significant modernisation in the SWA series. The new design features a quality rubber coating that provides a reliable grip even on cold nights and protects the eyepiece against impacts. The adjustable eyecups are noticeably more comfortable - a feature particularly appreciated by observers who wear glasses.
The Omegon SWA 20mm eyepiece is designed with parfocality across the entire SWA series in mind. When switching between different SWA focal lengths, you do not need to spend time refocusing - a practical advantage during comparative observation or when working with multiple eyepieces in a single night.
Who is this eyepiece for?
The SWA 20mm is an ideal choice as a low-power overview eyepiece for telescopes with shorter focal lengths, but it also performs excellently on longer instruments, where it delivers comfortable mid-range magnification with a generous field of view. It will be appreciated by:
- Beginning astronomers looking for their first quality eyepiece with a truly wide field
- Experienced visual observers building a collection of parfocal eyepieces for systematic observation
- Anyone observing under demanding outdoor conditions - the rubber body and robust construction are well suited for field use
About the Omegon brand
Omegon is a brand born from a passion for astronomy, focused from the very beginning on the practical needs of real observers. The SWA eyepiece series is direct proof of this philosophy - offering refined optics, modern mechanical design and well-thought-out details such as parfocality and comfortable eyecups, all at a price that makes quality wide-band optics accessible to a wide range of astronomers. The extensive range of Omegon accessories makes it easy to build a complete observing setup from eyepiece to filter - everything mutually compatible and proven in practice.
Key specifications
| Parameter |
Value |
| Focal length |
20mm |
| Apparent field of view |
70° |
| Barrel diameter |
1.25″ |
| Optical design |
5 elements in 3-4 groups |
| Coatings |
Fully multi-coated (FMC), broadband |
| Body |
Rubber-coated, blackened lens edges |
| Eyecups |
Adjustable, suitable for eyeglass wearers |
| Parfocal series |
Yes - within the SWA series |
