Engineered to Al Nagler's uncompromising standards, the entry-level Tele Vue Plossl 40mm Eyepiece has one of the longest focal lengths in the series to produce a low magnification for both near and deep-sky observations.
It is made using diffraction-limiting high-index glass lenses in a 4-element/2-group configuration to keep light on-axis and reduce astigmatism and edge-aberrations across its generous 43° apparent field of view. Fully multi-coated optics, blackened lens elements, and anti-reflection threads complement the optical components to improve contrast and light transmission, while limiting its loss. Its exceptional 28mm eye relief allows users the room to back off from the eyecup for a more comfortable viewing experience with a reduced risk of accidental contact with the eyepiece lens which can cause vibrations and interfere with views. Ideal for fast-focal ratio OTAs, the eyepiece features a standard 1.25" barrel to be compatible with the most popular size of focuser and accessories, a convenient fold-down rubber eyecup, and a rubberized textured collar to ensure a secure grip when handling it.