Pentax XW-5 Eyepiece

The Pentax XW-5 Eyepiece is a premium wide-angle eyepiece engineered for serious astronomical and terrestrial observers who demand optical precision, viewing comfort, and dependable performance in changing conditions. With its 5mm focal length, this eyepiece is ideal for high-magnification lunar, planetary, and double-star observation.

Immersive Wide-Field Performance

Featuring a 70-degree apparent field of view, the XW-5 delivers an immersive observing experience that allows celestial objects to remain comfortably framed, even at higher magnifications. This wide field is especially beneficial when using manually tracked telescopes, reducing the need for constant repositioning.

Long Eye Relief for Comfortable Viewing

Comfort is a defining feature of the XW series. The 20mm eye relief allows relaxed viewing during long observing sessions and makes the eyepiece suitable for eyeglass wearers without sacrificing image quality. Careful optical design also helps minimise blackout and vignetting by compensating for spherical aberration of the exit pupil.

High-Precision Lanthanum Optics

The optical system uses high-refraction, extra-low dispersion lanthanum glass elements to produce sharp, well-balanced images with minimal chromatic aberration. Pentax’s original multi-layer coatings are applied to all air-to-glass surfaces, while laminated elements receive specialised partial coatings, delivering exceptional light transmission and colour fidelity.

Advanced Coatings and Stray Light Control

Advanced computer-optimised lens geometry and an internal light-shielding diaphragm significantly reduce stray light and internal reflections. The result is a brighter, higher-contrast image with excellent edge performance and natural colour reproduction.

Weather-Resistant, Series-Matched Design

Built for real-world observing, the Pentax XW-5 eyepiece features JIS Class 4 weather-resistant construction, allowing confident use in damp conditions such as light drizzle or heavy night dew. As part of the Pentax XW series, the 5mm model integrates seamlessly into a broader eyepiece lineup, offering consistent optical quality across multiple focal lengths.