Re: [ATM] stalking the wild achromat: what price broadband correction?

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

Sounds like you're using your computer to prove out the thoughts
of  a lot of people before you.
The blue end of the spectrum is difficult to get to a goooood
focus ddue to the N curves varying so much in that region.
With triplets, you tend to make a split lens with one pair of the
glasses so that that glass and the third glass make a very nice
douoblet.
I am of the opinion that anybody contemplating a refractor really
not bother unless you reqally want poor performance - this from a
guy that is finishing up a 6" F8 refractor himself.  Leavve the
refractors to thesmall lens people for camera lenses and so forth
and let's get some design innovation with reflectors and mixed
telescopes.  That is where the better performance will be found
in a telescope.
Bob May
Due to the large volume of SPAM thaat I'm getting, add an open
square bracket to the subject line or my spam filter will reject
your post~
rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

_______________________________________________
ATM mailing list http://www.atmlist.net/