Re: ATM A Millies-LaCroix Diagram for Hyperboloids?

["James W. Burrows" <burrjaw@halcyon.com>]

At 17:23 1999-06-09 -0700, Scott Rychnovsky wrote:

>Texeraux uses a Foucault test to measure the primary for Cassegrain series
>telescoes.  If I remember right, he just does the normal "tex" analysis,
>but uses -b*hm/R2 instead of hm/R2, where b is the "something" constant. (b
>= -1 for a parabola).   I don't have it in front of me, but the equation is
>in Texeraux.
>
>He does the entire calculation including the transverse abberation.  I
>don't see why you couldn't apply this analysis to any hyperbola, and use
>the ± values from the Millies-LaCroix analysis to scale the TA.

It's hm^2/R (parabola, fixed source, Texereau, p. 102).  For a conic with
deformation constant b, the conic's normal crosses the optical axis at R -
bx (this is moving source, x = conic surface height), but if we're fussy, x
isn't quite equal to y^2/2R (y = hm = zone radius) for the non-parabolic
conic:

        x = y^2/2R + (b+1)y^4/8R^3 +...

The main reason for writing this is to warn people off of the ML "tolerance
bounds" - they lie.

        -- Jim Burrows          phone 206.244.2933, fax .0294
        --                      mailto:burrjaw@halcyon.com
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