Re: ATM Brandon Eyepieces

[Bratislav Curcic <epabcc@epa.ericsson.se>]

> The Brandons actually have more in common with Plössls than true
> orthoscopic designs

Orthoscopic actually means "distortion free". So Plossl can be 
orthoscopic, and Orthoscopic (read that Abbe) can be non-orthoscopic
(as certain non-brand, very popular, Japanese originated series of
these eyepieces are - "non-orthoscopic Orthos" - having quite appreciable
distortion).
For few remaining confused ATMers, it seems that design has very little
to do with actual performance, as all these 'planetary' eyepieces
haven't really changed optical formulae since inception (more than a
century ago for some types). Quality of polish seems to come to the
first place, quality of glass and antireflection coatings second. I
thought of saying this 'close second' but then I remebered certain non
coated Abbe Orthos that I've seen ... Make that quality of polish. And
then, classic Abbe Orthos, Tolles and Monocentric enjoy the advantage
of little or no ghost images. Not so important for some, crucially 
important for others. Can't please them all ...

Seriously, I sincerely doubt that anything short of planetary nutcase
with absolutely adorable first class instrument would warrant better
planetary eyepiece than already mentioned non-brand Orthos (stamped by
many as 'house brand'; the small Japanese comany is actually called
Tanny or something and has small 'T' imprinted onto eyepiece barrel. I
bought first of these almost two decades ago for US$14.95 ea, few more
recently at A$60). It took some _really_ picky observing to convince me
that my investment in Masuyamas was warranted ... Don't tell my wife !

Bratislav