Vixen SLV 20mm eyepiece 1.25″ - precision lanthanum optics for demanding astronomers
The Vixen SLV 20mm is a high-performance eyepiece designed for astronomers who refuse to compromise on image quality. Built around a 7-element lanthanum optical design, it delivers outstanding sharpness, contrast, and color accuracy across the full 50° apparent field of view - with no distortion and virtually no chromatic aberration. Whether you are observing planets, the Moon, or double stars, this eyepiece consistently performs at a level that satisfies both beginners and experienced observers.
Key features
- 7-element lanthanum optical system for superior image quality
- 50° apparent field of view - wide enough for comfortable observation
- Full multi-layer anti-reflection coatings on all optical surfaces
- 20mm eye relief with extendable rubber eyecup - comfortable for eyeglass wearers
- Standard 1.25″ barrel with filter thread for Moon, planetary, and UHC filters
- Durable, compact housing with a quality feel
Optical performance
The lanthanum glass used in the SLV series has a high refractive index and low dispersion, which allows Vixen engineers to correct chromatic aberrations more effectively than with conventional glass types. The result is an image that appears clean and sharp from center to edge, with natural color rendition and excellent contrast. Full multi-layer anti-reflection coatings minimize internal reflections and light loss, ensuring that as much collected light as possible reaches your eye in a useful form.
At 20mm focal length and 50° apparent field of view, the SLV 20mm produces a comfortable magnification level suitable for both detailed planetary work and general deep-sky viewing. It pairs naturally with telescopes of various focal ratios and maintains excellent image quality across a wide range of instruments.
Ergonomics and usability
The Vixen SLV series was designed with long observing sessions in mind. The 20mm eye relief is generous enough to allow observers who wear glasses to see the full field of view without discomfort. The extendable rubber eyecup helps to position the eye correctly and blocks stray light, further improving the perceived contrast of the image.
The standard 1.25″ barrel includes a filter thread, so the eyepiece can be used with a wide range of accessories - lunar filters, planetary filters, or narrowband UHC filters for nebula observation. This versatility makes the SLV 20mm one of the most practical eyepieces in its class.
Ideal applications
- Planetary observation - Jupiter, Saturn, Mars, Venus
- Lunar surface detail
- Double star splitting
- General purpose visual observation
- Star clusters and bright nebulae
Technical specifications
| Parameter |
Value |
| Focal length |
20mm |
| Apparent field of view |
50° |
| Barrel diameter |
1.25″ |
| Eye relief |
20mm |
| Number of optical elements |
7 |
| Glass type |
Lanthanum (SL) |
| Coatings |
Full multi-layer anti-reflection |
| Filter thread |
1.25″ standard |
| Eyecup |
Extendable rubber |
Who is this eyepiece for?
The Vixen SLV 20mm is particularly well suited for planetary observation and has earned a strong reputation in the astronomy community as one of the most reliable choices in the 1.25″ format. It is equally appropriate for beginners looking to invest in quality optics from the start, and for experienced observers who want a dependable, high-performing eyepiece that will remain a core part of their kit for many years. If you are looking for an eyepiece that delivers genuine optical quality without unnecessary complexity, the Vixen SLV 20mm is a choice you are unlikely to regret.
