Re: [ATM] Luri-Houghton prescriptions.

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

Thngs are starting to get interesting!
Ukyo is allowing the design of the lenses to whatevery they need
to go to and is getting near 0 astigmatism in his design but the
lenses are going to need more glass to do the menscusis lens
unless you do some slumping of the glass.  Richard is more trying
to stay within the basic more minimal glass usage and his designs
are giving some astigmatism but that astigmatism is on the order
of what I've been getting with my work with unequal curves.  Flat
surfaces are no problem as they only need to be close to flat to
work right as there is no need to do a 1/20th wave surface
accuracy.  Turning the ROC of the last surface concave to a
little bit doesn't really hurt the spot size very much although
you do have to calculate for new curves for the other surfaces.
Supprizingly, turning the curvature convex does hurt the spot
size more!  I haven't traced Ykyo's design yet but it does look
good in Oslo.
I'll note one thing.  Engineering units (2.0e03 and so forth) do
need some editing before I rally can use them and for many end up
being a lot harder to read.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

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