To: atm{at}shore.net
From: Jim Burrows 
Reply-To: Jim Burrows 


At 13:20 2003-05-03 -0700, Bob May wrote:

>The ROC of a Hindle sphere needs to be a bit shorter than the primary in
>order to do the test right.

Any spherical mirror will work as a Hindle sphere.  What you do is separate
the secondary and H. sphere so that the CoC of the sphere is at the
intended virtual focus of the hyperbolic secondary.  Then with the combined
source/KE at the other focus, you get a null test.  The requirements on the
Hindle sphere are all geometric - the RoC, diameter, and size of the hole
must be such that the whole surface of the secondary is being tested.

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

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