Re: ATM First project ( (NOT even a) Bit off too much? )

[Anthony Stillman <atmer@flash.net>]

All,

After plugging into OSLO LT, the prescription of the Lurie-Houghton
described in "TELESCOPE OPTICS" Rutten and van Venrooij, and spending a few
hours playing with various aspects of the design, I must retract my
statement that the radii of the correctors are tight.  It is true that
altering these radii do change the behavior of the system, but adjustments
in component spacing and field curvature, in all the variations I tried,
was sufficient to return the system to one with good performance.  That is,
one where the spot size was less than the Airy disk across a two degree
field.  I did not examine wedge (de-centering).  Perhaps another time.

I must also retract my inference that this design is more difficult to
fabracate than a 6" f/4 parabaloid.  I no longer believe that to be the
case.

I hope the list will forgive my error.

Anthony

PS  I am now officially tempted.