This 2” 24mm Explore Scientific is an excellent low power eyepiece with a wide, wide fully-immersive 82° field of view that’s particularly well-matched to big Dobsonian scopes and short focal ratio refractors. Viewing through this 24mm Explore Scientific makes you feel like you’re floating above the Earth, taking a space walk, rather than looking through a telescope eyepiece. This is an eyepiece that shows you a truly relaxed and unconfined “picture window” view of space.
While the longer focal length 30mm Explore Scientific provides an even wider field of view with an f/4.5 scope, the 30mm also has a very large 6.7mm exit pupil that is larger than many observers’ eyes can dilate. That effectively wastes some of a Dob’s light gathering capacity, as some of the full light cone falls on the observer’s iris, rather than entering his or her eye.
In addition to its wide field, the 24mm Explore Scientific has an extra benefit for you. 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 six 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 12" f/4.5 Dobsonian reflector will have a full 1.43° field at 57x with this eyepiece, able to encompass all of the Pleiades in one field. Even an 8” f/10 catadioptric will have a 0.98° field almost two lunar diameters across, for thrilling views of the larger nebulas, like Orion. You can use the calculator in the "formula" tab above to see just how wide the field will be with your particular telescope.
With 17mm of eye relief, this Explore Scientific eyepiece provides virtually unvignetted views for eyeglass wearers, although the 82° field of view is so wide that even non-eyeglass wearers can’t see the whole field at once. All observers have to move their eye from side to side to take in the immense view, so vignetting in the conventional sense is not a problem.
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 full details on this unique transferable lifetime warranty.