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Re: [ATM] back to longer FL

I null my spherometer on my already finished mirror, so I think I can get
the FL's pretty close using the spherometer, in any case well within 1%.

Jan
http://home.wanadoo.nl/jhm.vangastel/Astronomy/



----- Original Message ----- 
From: "Bob May" <bobmay@nethere.com>
To: <atm@atmlist.net>
Sent: Tuesday, June 28, 2005 2:54 AM
Subject: Re: [ATM] back to longer FL


> That makes things harder when you already have one mirror finished!  The
> only other choice is to match as best possible at the last stage of
grinding
> where you can move the focal length by an inch or more in a wet or two if
> you work at it.  Add in two more wets to insure sphericity and you are
ready
> to polish.  I wouldn't trust a ROC measurement that much until I got a
flash
> polish on the glass and a check on the Foucault tester.
> Bob May
> bobmay@nethere.com
> http://nav.to/bobmay
> http://bobmay.astronomy.net
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

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