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RE: A Schiefspiegler as first telescope (was Re: ATM 3-Vane or 4-Vane Spiders)

To: <atm@shore.net>
Subject: RE: A Schiefspiegler as first telescope (was Re: ATM 3-Vane or 4-Vane Spiders)
From: "Mel Bartels" <mbartels@efn.org>
Date: Sat, 6 Oct 2001 08:41:02 -0700
Importance: Normal
In-reply-to: <000201c14e73$47e0b980$cc5b8a90@PeterJohnSmith>
Reply-To: "Mel Bartels" <mbartels@efn.org>
Sender: owner-atm@shore.net


>>>
In other words, the extra work expended on longer focus
mirrors goes into a more accurate surface than required while with deep
ones
we do not directly see how bad it really is !  Any comments ???
<<<

Oh I think this is definitely true.  A f/4 at first blush seems rather
easy to make because the shadows are so deep, but in the end the surface
proves as slippery as a f/10, but with the provisio that the surface
quality needed is so much more touchy.

Mel Bartels

References:
- Re: A Schiefspiegler as first telescope (was Re: ATM 3-Vane or 4-Vane Spiders)
  - From: "Peter John Smith" <pjifl@bigpond.com.au>

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