This 11mm Explore Scientific is an exceptional medium high power/ultra wide field eyepiece that’s great for resolving globular clusters, picking up detail in smaller galaxies, investigating the Moon and planets in depth, and more. It works with any type of telescope, from a fast focal ratio Dobsonian reflector to a long focal ratio achromatic refractor or Maksutov. The wide field of the 11mm Explore Scientific makes observing through it feel like you’re gazing serenely through a “picture window on space” rather than squinting through an eyepiece. It provides an almost ideal match of an 8" f/10 Schmidt-Cassegrain’s resolving power to the resolving power of your eye, for maximum lunar and planetary detail.
In addition to its wide, wide field the 11mm 82° Explore Scientific comes with another very useful benefit. It is O-ring sealed and argon-purged to be 100% waterproof. This prevents internal fogging in the eyepiece; keeps the interior dust-and fungus-free; and makes it easier to clean, as there is no risk of excess cleaning solution getting trapped between the lenses.
The latest computer design programs have been used to optimize its performance. Its seven element/four group design uses low dispersion and high refractive index lenses and full multicoatings for high contrast, high resolution, and flat field images across its very wide 82° field of view. The lens edges have been blackened to improve contrast.
A 10" f/4.5 Dobsonian reflector gives you a full 0.79° field at 103x with this eyepiece, half again as wide as the full Moon, for eyepiece filling views of showpiece nebulas like Orion. Even an 8” f/10 catadioptric has a 0.45° field at 182x that’s almost as wide as the full Moon itself, for thrilling close-up views of our nearest celestial neighbor. Use the calculator in the "formula" tab above to see just how wide a field you’ll get with your particular telescope.
At 15mm, the eye relief is surprisingly good, although eyeglass wearers will still see a somewhat vignetted image. This isn’t as much a problem as you might think, as the 82° field of view is so wide that even non-eyeglass wearers have trouble seeing the whole field at once. This is an eyepiece that shows you a “picture window view” of space for a true full-immersion observing experience. With its unconstricted view, your eye relaxes, allowing you to easily use the “averted vision” technique to study faint details across a huge field of view.
The eyepiece has a soft fold-down rubber eyecup and comes with dust covers for both ends of the eyepiece.
This individually serial numbered Explore Scientific eyepiece is backed by a limited one year warranty, which will be extended to an Explore Scientific transferable lifetime limited warranty when its warranty card is registered with Explore Scientific within 60 days of purchase. Here's a link to the full details on this unique transferable lifetime warranty.