Vixen SLV 25mm eyepiece - 1.25″, 50° apparent field of view
The Vixen SLV series represents a premium line of eyepieces designed for astronomers who refuse to compromise on image quality. The 25mm focal length model offers a comfortable wide-overview magnification with excellent image brightness, making it one of the most versatile eyepieces you can add to your collection. Whether you are observing planets, the Moon, double stars or extended nebulae, the Vixen SLV 25mm delivers sharp, high-contrast views across the full 50° field of view - right to the very edge.
Lanthanum optics - the foundation of the SLV series
The optical system of the Vixen SLV series consists of 7 elements made from special lanthanum glass with a high refractive index. This material allows effective correction of chromatic aberration without requiring a large number of additional corrective elements, keeping the design compact while maintaining outstanding optical performance.
All optical surfaces are treated with fully multi-coated anti-reflection coatings (FMC), which minimise stray reflections and ghosting to an absolute minimum. The result is an image with exceptional clarity - natural colour rendition, high contrast and a level of light transmission that rivals much more expensive alternatives.
Key features and specifications
| Parameter |
Value |
| Focal length |
25mm |
| Apparent field of view |
50° |
| Barrel diameter |
1.25″ |
| Eye relief |
20mm |
| Number of optical elements |
7 (lanthanum glass) |
| Optical coatings |
Fully multi-coated (FMC) |
| Filter thread |
1.25″ standard |
| Eye cup |
Retractable rubber eyecup |
Comfortable observation - including for eyeglass wearers
With 20mm of eye relief, the Vixen SLV 25mm is fully compatible with observation while wearing glasses. The generous eye relief ensures that the entire 50° field of view remains accessible without the need to press your eye close to the lens. The retractable rubber eyecup allows precise adjustment of eye distance and effectively blocks stray ambient light, which is particularly important during suburban observations.
Filter compatibility
The 1.25″ barrel is equipped with a standard filter thread, allowing direct attachment of any 1.25″ astronomy filter without the need for adapters. The SLV 25mm pairs naturally with:
- Planetary filters (green, orange, red, blue)
- Lunar filters (neutral density)
- Broadband nebula filters (UHC, CLS)
- Light pollution reduction filters
Where the Vixen SLV 25mm performs best
Planetary and lunar observation
At 25mm focal length, this eyepiece typically delivers a comfortable mid-range magnification suitable for detailed study of planetary surfaces and lunar terrain. The high contrast rendering and excellent chromatic correction of the lanthanum optics bring out subtle cloud belts on Jupiter, polar caps on Mars and fine crater detail on the Moon with impressive clarity.
Deep sky overview
The 50° field of view and relatively long focal length make the SLV 25mm an excellent choice for framing extended objects such as open clusters, bright nebulae and larger galaxies. The image brightness is well-maintained thanks to the FMC coatings, ensuring that faint detail is not lost to internal reflections.
Double stars
The well-corrected optics across the full field make this eyepiece a reliable tool for splitting double stars, particularly for wider pairs where a comfortable magnification combined with a steady, high-contrast image is more beneficial than extreme power.
A versatile member of your eyepiece collection
The Vixen SLV 25mm is widely regarded as one of the most practical focal lengths in the SLV range. It fills the role of a general-purpose overview eyepiece that you will reach for regularly - as a starting point for any observing session, for orientating in the sky, or as a standalone eyepiece when using a longer focal length telescope. Its build quality, optical performance and practical eye relief make it a long-term investment rather than a compromise purchase.
About the Vixen SLV eyepiece series
The SLV (Super Long eye relief Vantage) line is part of Vixen's professional eyepiece portfolio, developed in Japan with a focus on optical precision and practical usability. The series is available in focal lengths ranging from 2.5mm to 40mm, all sharing the same 7-element lanthanum optical design and fully multi-coated surfaces. This consistency makes it straightforward to build a coherent, matched eyepiece set with predictable and uniform optical characteristics across all magnifications.
