Re: [ATM] Eyepieces

["Bob May" <bobmay@nethere.com>]

You're right in that the UO Koniegs are an excellent EP.  Their
downsides are that they have a short eye relief isn't that great
so any under about 9 mm are pretty much useless.  I'd get a good
barlow, 9mm ortho, 15mm Konieg, 25mm Konieg for a nice set of
EPs.  My experiments with a set of 18mm EPs of the various
designs has shown the Konieg is usually the first choice, the
Erfle is the second choice, the Ortho is third, either the
Kellner or the Plossl is fourth.  Always sitting at the bottom of
the pile is the lowly Ramsden.  Sometimes the Erfle is on top but
that often happens with those that use eyeglasses as they have a
good eye relief that the Koniegs don't have.
Note that the size selection provides for a 4.5, 7.5, 9, 12.5 15,
25mm sizes when you include the barlow in the mix.  Thus, for 4
pieces, you get a lot more selections of focal length and the
bonus is that the shorter FL combinatons have the longer eye
relief of the EP that is being used with the barlow.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
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