The Astro-Tech 1.25" Series 6 eyepieces are excellent values, typical of Astro-Tech’s “more performance for less money” philosophy. Each uses a four element/three group optical design to provide a wide field of view and reasonable eye relief, particularly with scopes having a focal ratio of f/6 and higher, and a very
economical price. Series 6 eyepieces are parfocal, to minimize the need for refocusing when you change eyepieces.
All Series 6 lens elements have blackened lens edges and the interiors of the barrels are finished in matte black with anti-reflection threading for low internal reflections. The result is high contrast, with a dark sky background to make low surface brightness objects stand out more clearly. All lenses are fully multi-coated with the latest broadband high transmission/anti-reflection coatings for excellent light transmission and low ghosting.
Each Astro-Tech Series 6 eyepiece has a soft fold-down rubber eyecup for eyeglass use. Protective dust covers are provided for both ends of each eyepiece.
There is a safety groove machined into each 1.25” barrel. This engages the thumbscrew or compression ring of your star diagonal or focuser drawtube to keep the eyepiece from falling should the thumbscrew accidentally loosen during use.
Unlike similarly-priced eyepieces whose focal lengths are only silk-screened onto the barrel, and are prone to get rubbed off during use, each Astro-Tech’s model and focal length are laser-etched into the eyepiece body. The aluminum body material revealed by the etching provides permanent visibility against the body’s black anodized exterior.
All in all, the Astro-Tech Series 6 eyepieces offer surprisingly good value and performance for a very low price.