From: "Bob May" 
To: "atmlist" 
Reply-To: "Bob May" 


If you are working with a single approximate F ratio, then a single lens
(doublet) is more than good enough for the typical application.  There will
be no real distortion with lenses of the longer FL and the requirement of
the lens is that it be big enough to accept the light cone from the KE
which, at the KE itself will be a near point. I have a lens doublet of
about 1" on my security camera and it works fine for anything down to
about F12 or so when the image starts getting a bit small.
Bob May
http://nav.to/bobmay
bobmay{at}nethere.com
NEW! http://bobmay.astronomy.net

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