Pentax XW-3.5 3.5mm 70° 1.25" Eyepiece

The Pentax XW-3.5 3.5mm 70° 1.25" Eyepiece is a premium wide-angle eyepiece designed for serious astronomical and terrestrial observers who demand exceptional image quality, comfort, and durability. As part of the renowned Pentax XW series, this eyepiece delivers outstanding optical performance for high-magnification lunar, planetary, and double-star observations.

Immersive Wide-Angle Performance

Featuring a 70-degree apparent field of view, the XW-3.5 provides an immersive viewing experience that keeps celestial objects comfortably framed, even at high magnifications. This wide field is especially beneficial when observing with manually tracked telescopes, reducing the need for constant repositioning.

Advanced Lanthanum Optical Design

Built with high-refraction, low-dispersion lanthanum glass elements, the Pentax XW-3.5 produces bright, high-resolution images with excellent colour fidelity and minimal chromatic aberration. Pentax’s proprietary SMC multi-layer lens coatings maximise light transmission while suppressing internal reflections, delivering sharp contrast and clarity across the entire field of view.

Exceptional Viewing Comfort

Comfort is a standout feature of the XW series. The generous 20mm eye relief allows for relaxed, fatigue-free viewing and makes this eyepiece suitable for eyeglass wearers without sacrificing image quality. This makes it ideal for extended observing sessions at high magnification.

Weather-Resistant & Versatile Construction

Designed for real-world use, the eyepiece features JIS Class 4 weather-resistant construction, offering protection against moisture and environmental exposure. The standard 1.25-inch barrel ensures broad compatibility with a wide range of astronomical telescopes and accessories.

An evolution of the earlier XL series, the Pentax XW-3.5 retains the proven ergonomic design while improving optical performance with a wider field of view, enhanced light transmission, and advanced computer-optimised lens geometry. The result is a high-performance eyepiece that delivers consistently sharp, bright, and immersive views.

The Pentax XW-3.5mm Eyepiece is an excellent choice for observers seeking premium optics, long-term comfort, and professional-grade performance in a compact, precision-engineered design.