Pentax XW-16.5 Eyepiece



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Clear, comfortable viewing assured by 85° or 70° apparent angle of view and 20mm eye relief

85-degree apparent angle of view eyepieces, XW23 and XW16.5 is newly added to the smc PENTAX XW-series line up featuring an extra -wide 70-degree apparent angle of view with an extra-long 20mm eye relief to deliver an exciting wide-perspective image.


Long-focal-length eyepieces, ideal for nebula and star cluster observations

Thanks to their long-focal-length design, the XW40-R and XW30-R eye-pieces will let you observe large celestial bodies spreading across the night sky, such as the Pleiades star cluster and the Andromeda Galaxy, in their entirely.*

* When mounted on an astronomical telescope with a focal length of 10000mm.

High-grade optics for exceptional image quality

The high-performance XW-series optics incorporates high-refraction, extra-low-dispersion lanthanum glass elements to produce a well-balanced image with minimal aberrations. It is particularly designed to reduce the disturbing blackout effect by effectively compensating the spherical aberration of the pupil.

PENTAX-original multi-layer coating for outstanding light transmission efficiency

All lens surface that come in contact with air are treated with the original multi-layer coating, while all laminated surfaces are treated with the innovative partial coating. to offer the light transmission efficiency of more than 90 percent (96 percent at 550nm) over the visible light spectrum.

Advanced light-shielding technology for improved image contrast

Thanks to PENTAX’s advanced computer simulation technology, the XW series features a light-shielding diaphragm at the most effective position to drastically reduce internal reflections for a brighter, higher-contrast image.

Weatherproof construction for all-weather viewing

The XW series features JIS Class 4 weatherproof construction,* making it possible to use it in drizzle or under night dew.

* The XW-series eyepieces are not designed for underwater use and should not be submerged under water.

Sleeve size and eyecup design

The XW series provides as choice of two installment diameters: American-standard 31.7mm version, and 50.8mm (two-inch) version. When you remove the screw-on eyecup. it also provides a screw thread with a 43mm diameter and a 0.75 pitch.

Comprehensive lineup to accommodate all applications

Featuring functional, practical focal lengths, the XW eyepieces series provides a comprehensive lineup that accommodates all types of applications, from low-magnification viewing of stars to high-magnification observation of planets.