"Doc" wrote in message
om...
How do you tell if you have a Plossl eyepiece?

Thanks

It's easier to tell if you don't.

There is no sharp line between Plossl and Symmetrical and some other
four-element designs.

A Plossl has two components, each of which is a doublet (a two-element
cemented achromat) and they are roughly comparable in thickness. The eye
relief is very roughly 75% of the focal length.

If the element away from the eye is a single (thin) lens, you have a Kellner
or variation thereof (Modified Achromat is a common name).

If the elements are a singlet and a triplet, then you have an Orthoscopic.

And if it's more complicated, you have something else



--
Clear skies,

Michael Covington -- www.covingtoninnovations.com
Author, Astrophotography for the Amateur
and (new) How to Use a Computerized Telescope