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


Hi Byron:

Is your knife coming in from the left or the right?

This will determine if features are raised or depressed based on the shadows.

ttfn
Greg

----- Original Message -----
From: Byron Ader 
Date: Thursday, July 17, 2003 12:06 pm
Subject: ATM Focault Test Update

>
> http://f1.pg.photos.yahoo.com/byronader Be sure to click the Astronomy
> folder and the click the thumbnail.
>
> here is a scanned page of my focault test.  I am sure there are
> things I
> need to differently with this test.  For instance, my knife edge
> is not
> perfectly strait up and down on both axis.
>
> The Pictures on the left are outside of the ROC.
>
> The picture on the top left is ROC (As best as I can tell.  It is
> where the
> shadow seems to just pop up over the whole surface at once.)
>
> If you can not read my scribbles, they basically represent what I
> saw in mm
> inside or outside of ROC.  If I were to rotate the mirror, the
> zones that
> are reflected here stay consistent.
>
> Can you tell me what figuring stroke I need to undertake to
> resolve this
> issue?
>
> When migrating to the outside of ROC further, the "hill" in the
> middle of
> the mirror shows up to be spherical just further out than the
> regular ROC.
> I am completely new at this so I am actually using the outside of
> my mirror
> as the reference sphere.
>
> I hope my scribbles give you a basic understanding of what is
> going on.
>
> Thanks for your help,
> Byron
>
>

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