From: Emery Greg 
To: Byron Ader 
Cc: atm{at}shore.net
Reply-To: Emery Greg 


Hi Byron:

I had a look at the sketches.  I'm not very experienced with looking at the
doughnut shadows.  I have no experience with an f/4.

 My initial guess ( and that may unfortunately be the accuracy of it all ) is
that there is a central hill ( you said the knife was from the left, correct?).
 The outside shadows at least look to be in the right areas.  You really should
make a Coude Mask (4 zones or so) and collect the data that way.  You can
then analyze the data and have a more reliable estimate of the mirror
surface.

Personally, I would do the Coude mask and analyze the data before I touched
the mirror again.  You can read about zonal testing in ATM 1, ATM 2 and
Texereau.

Anyone shed more light on this than I can (sorry for the bad pun)?

ttfn
greg

----- Original Message -----
From: Byron Ader 
Date: Monday, July 21, 2003 5:53 pm
Subject: ATM Figuring problems

>
> I just wanted to confirm my test results, I would hate to move
> forward an
> increase my problems.  Has anyone had a chance to review the
> results of my
> Focault test at www.astrothuse.com ?  If you had any feedback, I would
> appreciate it.
>
> Thanks,
> Byron
>
>

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