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Re: [ATM] Calculate Astigmatism

To: "Robert Turner" <rbturner@charter.net>, "ATMList Post" <atm@atmlist.net>
Subject: Re: [ATM] Calculate Astigmatism
From: "Donald \"Don\" Ware" <mimas@charter.net>
Date: Fri, 19 Mar 2004 09:47:46 -0500
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----- Original Message ----- 
> From: "Robert Turner" >
> I was wondering if it would be possible to calculate astigmatism from
> focault readings. My first guess was to take focault readings at different
> orientations and then determine the amount of astigmatism. >
_______________________________________________

You can definitely see different foucault results from an astigmatic mirror
by comparing readings from different axes.  The results also roughly
correlate with interferometer results.  However, roughly is the keyword.
Foucault testing assumes the mirror is symmetric about an axis perpendicular
to the test axis, while astigmatism is rarely symmetric.

Regards,

Don Ware
Hollis, NH
http://webpages.charter.net/dware1/



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References:
- [ATM] Calculate Astigmatism
  - From: "Robert Turner" <rbturner@charter.net>

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