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Re: [ATM] A foucault image quiz Part 1.

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Subject: Re: [ATM] A foucault image quiz Part 1.
From: Neil Booker <neil@astronomy.ndo.co.uk>
Date: 09 Apr 2008 18:21:05 +0100
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Hi All
Just to show my in-experience:-

-----Original Message-----
> I wonder how many of you experienced Foucault testers

My first mirror was a 6inch F10 & I couldn't get the hang of the Foucault test at all. My second & last (hopefully that'll be latest) was F5.5 & I finally got it so I've only really tested one mirror so I'm not sure why I'm answering this post. 

With the F10 I later learned that if I could see the shadows then I'd gone too far so my guess is it's very over corrected or a lot less than F10. I also thought that the bright ring was caused by a good edge i.e. not turned.

Looking forward to being corrected (oops, sorry for the pun) & hence learning.

Neil
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