Vixen SLV 2.5mm eyepiece 50° 1.25″

Vixen SLV 2.5mm eyepiece 50° 1.25″

If you are looking for an eyepiece that will truly show you everything your telescope is capable of when observing planets, the Vixen SLV series is the answer. The SLV 2.5mm is designed for observers who refuse to compromise on image quality and demand sharpness, contrast and accurate colour rendition even at high magnifications. Its 2.5mm focal length makes it an ideal tool for detailed study of the lunar surface, planetary discs and double stars.

Lanthanum optics - the foundation of exceptional image quality

The Vixen SLV eyepiece with 8-element lanthanum optics represents one of the most sophisticated optical systems in its class. Lanthanum as an additive to optical glass makes it possible to achieve a high refractive index while maintaining low dispersion, which directly results in minimised chromatic aberration. The result is an image in which star points remain pinpoint even at the edge of the field of view, and colour fringing around bright objects is practically undetectable. This is particularly important when observing Jupiter or Saturn, where any unwanted colour artefact distracts from real details - cloud bands, storms or ring structure.

The entire optical system features full multi-layer anti-reflection coatings on all optical surfaces. These coatings significantly reduce light losses caused by reflection and internal light scatter within the eyepiece, allowing it to achieve very high light transmission. In practice this means a richer, more contrastive and brighter image even when working with a telescope operating at the limit of its resolving power.

50° apparent field of view - the right choice for planetary work

A 50° apparent field of view is an excellent choice for a planetary eyepiece with such a short focal length. Planets are concentrated in the centre of the field where the imaging geometry is most accurate, while the observer still has enough room to follow the movement of an object without constantly intervening in the guiding system. Compared to ultra-wide-angle eyepieces with 82° or 100° fields of view, the 50° variant has the advantage that the optical system is simpler and better corrected - every compromise typical of extremely wide-angle designs is eliminated here in favour of image purity and contrast.

20mm eye relief - exceptional comfort for prolonged observation

Eye relief - the distance of the exit pupil from the last lens element - is a very important parameter for comfortable and extended observing sessions. The Vixen SLV 2.5mm offers an eye relief of 20mm, which is a truly exceptional result for such a short focal length. Most competing eyepieces with similar specifications offer eye relief in the range of 8 to 12mm, which can be uncomfortable especially for eyeglass wearers or during longer observing sessions. With 20mm eye relief you can observe comfortably even while wearing glasses, without having to worry about incorrect eye positioning. The retractable rubber eyecup allows easy adjustment depending on whether you wear glasses or not.

1.25″ standard barrel with filter thread

The eyepiece is made in the standard 1.25″ diameter, which is the most widely used standard in amateur astronomy. It therefore fits the vast majority of refractors, reflectors and catadioptric telescopes with the appropriate focuser or adapter. The eyepiece includes a 1.25″ filter thread - for example for a neutral Moon filter, a polarising filter or a planetary colour filter. This seemingly small feature is particularly appreciated when observing the Moon, where brightness on a clear night can be very intense.

Recommended use and telescope pairing

The Vixen SLV 2.5mm is aimed at observers who want to work at high magnifications under stable atmospheric conditions (good seeing). With a typical telescope having a focal length of 1000mm you will achieve 400x magnification; with 1500mm you reach 600x. Such magnifications are meaningful only under excellent seeing, but it is precisely then that this eyepiece will reveal details that would otherwise remain hidden. We recommend pairing it with a telescope of medium to large aperture - from 100mm upward for planets, from 80mm for the Moon.

Suggested telescope and target combinations

• Apochromatic refractor 100-150mm + SLV 2.5mm - ideal for Jupiter and Saturn detail
• Newtonian or Dobsonian reflector from 150mm - maximum resolution on Mars and the Moon
• Schmidt-Cassegrain or Maksutov-Cassegrain with long focal length - excellent for double stars and lunar surface

Who is this eyepiece for?

The Vixen SLV series has long been regarded by experienced amateur astronomers as one of the best standards for visual planetary observation. This is not an eyepiece for a beginner who is still deciding what to observe - it is an eyepiece for someone who already knows that planets are their passion and is looking for a tool that will show them the maximum. If you own a quality refractor or apochromatic objective and want to get the most out of it when observing Saturn, Jupiter, Mars or the Moon, the SLV 2.5mm is an investment that will pay off every clear night with good seeing.

The Vixen SLV 2.5mm is an eyepiece you insert into the focuser once and immediately understand why experienced observers speak about this series with such respect. The image is clean, contrastive, free from disturbing artefacts and surprisingly comfortable to use. That combination is very hard to find in this price category.

Technical specifications