The XW23 and XW16.5 eyepieces feature an 85-degree apparent angle of view. Other models in the smc PENTAX XW-series feature an extra-wide 70-degree apparent angle of view. All models in the series offer an extra-long 20mm eye relief to deliver an exciting wide-perspective image.
Thanks to their long-focal-length design, the XW40-R and XW30-R eyepieces will let you observe large celestial bodies spreading across the night sky, such as the Pleiades start cluster and the Andromedia Galaxy, in their entirety*
*When mounted on an astronomical telescope with a focal length of 10000mm.
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.
All lens surfaces 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 (an astonishing 96 percent at 550nm) over the visible light spectrum.
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.
With eight different magnifications (3.5mm, 5mm, 7mm, 10mm, 14mm, 16.5mm, 20mm, 23mm, 30mm and 40mm) to choose from, the XW series accommodates a wide range of both casual and specialized applications.
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.
The XW series provides as choice of two installment diameters: American standard 31.7mm version (1.25 inch), 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.
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.