With its exceptional apparent angle of view, the Tele Vue Ethos 21mm Eyepiece offers a comfortable eye-relief with high contrast and excellent on-axis sharpness; and virtually zero astigmatism or field curvature across its expansive 100° field of view.
It features anti-reflection fully multi-coated optics to improve brightness, color rendition, and contrast; and a fold-down rubber eyecup that helps to block stray peripheral light from interfering with the views and to further enhance contrast. Combining a hyper-wide apparent angle of view with a long focal length, the eyepiece delivers moderate to low magnifications on most telescopes — offering expansive views of the night sky and an immersive observational experience. This eyepiece features a large 2" barrel diameter to make it even more comfortable to view through, and a textured rubberized grip for sure handling. It is compatible with the astigmatism-correcting DIOPTRX diopters to further improve the view.