Re: Foucault test limitations was [ATM](no subject)

[Jim Burrows <burrjaw@earthlink.net>]

At 2004-05-14 13:05 -0400, Vladimir Sacek wrote:

>Quite a bit of discrepancy. It seems that the main reason for the
>significantly smaller test numbers is the treatment of transverse
>aberration. It is assumed to be half of  that given by the longitudinal
>aberration at c.o.c., while the geometry clearly suggests it is twice
>larger at infinity focus than at c.o.c. I don't see the reason for this
>"minimization" of the transverse aberration. Can someone enlighten me?

The light, following wave optics, doesn't go where (geometric) transverse 
aberration says.  For a net blast, see

         http://home.earthlink.net/~burrjaw/t_verse.lwp/t_verse.htm

Exact surface RMS for your 300 mm f/4.5 with b=-0.96 is 9.59 nm.  Mahajan's 
approximation gives Strehl = .950, so the non-TA result is pretty close.

         -- Jim Burrows
         -- mailto://burrjaw@earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84)  

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