Explore Scientific 82° Series 30mm Waterproof Eyepiece Argon-Purged

Using advanced computer design, combinations of low dispersion and high refractive index optical glasses, and durable multilayer deposition coatings, Explore Scientific 82° Series™ extreme wide field eyepieces are optimized to produce high contrast, high resolution, and superior flat field characteristics. The visual effect of these eyepieces with their long eye-relief and their 82° apparent field is truly a full-immersion experience. Your eye is relaxed, allowing you to easily use the "averted vision" technique to study faint details across a huge field-of-view. Each eyepiece is meticulously assembled into precision machined metal lens barrels that maintain the perfect alignment of the optical train for years of rugged use in the field. The 82° Series eyepieces come with a twist-up rubber eye-guard that raise to the desired height for the comfort of the observer, and as experienced astronomers know, eye comfort is critical when trying to observe at the visual limits of the telescope. To keep internal reflections to a minimum, all internal surfaces of the eyepiece barrel are flat black, as well as the edges of the lenses themselves to minimize the scattering of light within the lenses themselves. Specifications Barrel Diameter: 2" Eye Relief: 21mm Lens Elements: 6 in 4 Groups Weight: 2.2 lbs.