Re: [ATM] f12 mirror advice requested

["Mitch" <funnybone101@earthlink.net>]

-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
Philip Lardner
Sent: Friday, February 02, 2007 3:37 PM
To: ATM
Subject: Re: [ATM] f12 mirror advice requested

Yes - I recently finished a 14" f/15 (RofC=10,500mm) and found not just the
focal length but the figure to be extremely sensitive to change while
polishing. I ended up with a RofC = 10502mm and decided that was good
enough! Testing a mirror of that length wasn't easy either. The slightest
air currents really screwed things up, and it also showed up the surface
roughness in the video camera (and other lenses I used) as clear as day!

Phil.

***Just curious, are you making a 17.5 foot high telescope, or is this for
some folded or off-axis design?

Mitch

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