PENTAX Corporation is pleased to announce the introduction of the smc PENTAX XW series of eyepieces designed for use with PENTAX-brand spotting scopes and telescopes in ground and astronomical observations. Consisting of eight models with a focal length ranging from 3.5mm to 40mm the new XW series features a wide apparent angle of view (70 degrees) JIS Class 4 weather-proof construction and a long eye relief (20mm). The new optics incorporating high-refraction low-dispersion lanthanum glass elements and PENTAX-original multi-layer coating delivers bright high-resolution images with minimal aberrations and distortions. The new XW series retains all the popular features of the current XL series including eyepiece shape while upgrading many vital specifications. All XW models feature a 70-degree apparent angle of view delivering a more dramatic wide-perspective image than the 65 degrees of the XL series. Laminated optical elements are treated with the innovative partial coating which offers much higher light transmission capability than conventional full-surface coating. Thanks to advanced computer simulation technology internal reflections are drastically reduced to produce brighter clearer images. Replacing the existing XL series the new XW series can be used with the PENTAX PF-80ED PF-80EDA and PF-100ED spotting scopes and a range of PENTAX telescopes to optimize their performance and capability. The XW7 XW10 XW14 and XW20 models are suited for both ground and astronomical applications while the XW3.5 XW5 XW30 and XW40 models are exclusively designed for astronomical observations.Lens Structure - 6 Elements 5 GroupsFocal Length - 40mmApparent Field of View - 70 DegreesEye Relief - 20mmAttachment Diameter - 2" (50.8mm)Filter Diameter - 48mmField Stop Diameter - 46.5mmWeight - 24.7 oz. (700g)