Pentax SMC-XW Series 23mm Wide Angle Eyepiece with 85 Degree Field of View

The new eyepieces of the XW series have the largest field of view in the series at 85 Degree . In combination with an eye relief of 20 mm, they provide a particularly wide field of view for exciting observation of nebulae and star clusters.High-performance, wide-angle eyepieces for use with high-grade spotting scopesmc PENTAX XW series - 70 Degree or 85 Degree Apparent Angle of View, 20mm Eye Relief, plus Weatherproof Body for Multi-Application ViewingLong-focal-length eyepieces, ideal for nebula and star cluster observationsXW23 and XW16.5 are newly added to the smc PENTAX XW-series line up featuring an extra -wide 85-degree apparent angle of view with an extra-long 20mm eye relief to deliver an exciting wide-perspective image.And 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 Andromedia Galaxy, in their entirely. When mounted on an astronomical telescope with a focal length of 10000mm.High-Grade Optics for Exceptional Image QualityThe 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 EfficiencyAll 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.Advanced Light-Shielding Technology for Improved Image ContrastThanks 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.Comprehensive Lineup to Accommodate All ApplicationsFeaturing functional, practical focal lengths, the XW eyepiece series provides a comprehensive lineup that accommodates all types of applications, from low-magnification viewing of stars to high-magnification observation of planets.Weatherproof Construction for All-Weather ViewingThe XW series features JIS Class 4 weatherproof construction, making it possible to use it in drizzle or under night dew.Note: The XW-series eyepieces are not designed for underwater use and should not be submerged under water.Sleeve Size and Eyecup DesignThe XW series provides a 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.