With its incredible 110° apparent field of view, the Tele Vue Ethos-SX 3.7mm Ultra Wide-Angle Eyepiece provides distortion correction, high contrast, and excellent on-axis sharpness for planetary viewing. Screw the innovative adapter onto the filter threads to convert the eyepiece from a 1.25" barrel to a 2.0" barrel for larger focusers.
With its short focal length, the Ethos-SX 3.7mm delivers higher magnification for enhanced detail on deep sky objects while maintaining its ultra-wide field of view. Engineered to provide stunning views, the Ethos-SX is built with fully multi-coated optics, blackened lens edges, and anti-reflection threads which work together to maximize light transmission while limiting internal light diffraction. A long 15mm eye relief and convenient fold-down rubber eyecup add to the already impressive features of this eyepiece.
Like all Ethos eyepieces, the 3.7mm SX also accepts astigmatism correcting DIOPTRX diopters to further enhance and refine your views. When used as a 1.25" eyepiece, it is parfocal (requiring little or no refocusing when changing eyepieces) with the wide range of Tele Vue 1.25" Plössls, Panoptics, Radians, Naglers, Nagler Zooms, and the 6mm and 8mm Ethos eyepieces. The 2" adapter is designed to make it parfocal with the 13mm and 10mm Ethos, when they are also used with their 2" adapters.