[Raytrace] Waineo Null

[Peter John Smith]

John D. Upton wrote about this particular configuration of the 'Waineo'
test.


>Pinhole (fiber optic pointing to user's right toward sphere) diameter .010
>Reference sphere (facing left) Dia = 12.5"
>Reference sphere RC=132.72"
>Knife edge is 7" behind surface of sphere
>Paraboloid (facing right) Dia = 17.5"
>Paraboloid RC= 157.37"

>      The setup says that the 12.5" reference sphere is large enough --
only
> an 11" element is required to cover your 17.5" mirror.  The optical fiber
> source needs to be set just under 48" from the reference sphere and the
> spacing from reference sphere to your mirror is about 103".  This set of
> values gives a knife edge position of about 7" as requested.
>
>      Here is the setup in human-readable form:
>
> *LENS DATA
> No name
>   SRF      RADIUS      THICKNESS   APERTURE RADIUS       GLASS  SPE  NOTE
>   OBJ       --         47.998151 V    0.005000             AIR
>   AST  -132.720000   -102.950000      5.484369 AS   REFL_HATCH
>    2    157.370000    109.996872 S    8.750000 S    REFL_HATCH   *
>   IMS       --          0.000417      0.007224 S
>
> *CONIC AND POLYNOMIAL ASPHERIC DATA
>   SRF        CC          AD          AE          AF          AG
>    2      -1.000000      --          --          --          --

> that the best residual P-V error was better than 1/100 wave (at the


You can rest assured that it is correct.  Zemax confirms the PV error is
very close to 1/100 wave (on the wavefront emerging from the Parabola in the
test setup).


With software like OSLO around tests like these become readily available.
But I fear that ATM's will never really take advantage of null testing


I have never used the test but know someone who has and he is very happy.
He did a tolerance analysis as well to see what figuring errors might result
from spacing errors.  Which would be a good exercise to do on this
configuration.

If anyone wants to play with a variety of nulls all aimed at possible ways
to figure Cass secondaries, see my web site then go to page 13 - see below

 <http://www.users.bigpond.com/pjifl>

Somewhere in that article I mentioned the 'Waineo' null test in passing on
to variants.  I specifically did NOT call it a Waineo test because it was
around long before Tom Waineo commendably tried to educate the ATM movement
about it.

Maybe this was counterproductive on my part because people probably
recogmise it more easily under this name.  And it would seem that Tom was a
really nice guy.  But the ATM world is insular enough as it is.  On the
other hand, I dont really know what it should be called so maybe calling it
the Waineo test is reasonable........


I would really love to try this test myself.  Maybe the next project in
line.......


Peter Smith.





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