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


At 22:07 2003-06-30 -0500, Jerry B. Hillman wrote:

>I need some help understanding what some of these numbers mean.
>With parabola checked
>...
>Strehl .999

You can ignore the other numbers - the Strehl ratio says you're done
(passing is .8), really done (same as last time) as far as a
single-diameter bench test can judge.

>The star test tonight showed slight astigmatism at high power that went away
>when I rotated the mirror about 30ø.

Hmm, interesting - these thin mirrors can be complicated.  Possibly the
astig might come back at different
altitudes.  When you do the Ronchi test on a star, make sure the Ronchi
ruling is as vertical as possible - I think primary astigmatism only tilts
the shadows.

>I have the six test file saved for anyone that might want to check my
>entries. I think this mirror is done.

Yeah, chuck it to me, but I can't imagine anything is wrong.

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

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