[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: [ATM] Off-centered Mirrors?

To: DHA352@aol.com
Subject: Re: [ATM] Off-centered Mirrors?
From: Wouter van Reeven <wouter@van.reeven.nl>
Date: Sat, 23 Oct 2004 22:25:20 +0200
Cc: AMT Mailinglist <atm@atmlist.net>
In-Reply-To: <9.353451d1.2eac1113@aol.com>
List-Archive: <http://home.simoivanov.com/pipermail/atm>
List-Help: <mailto:atm-request@atmlist.net?subject=help>
List-Id: The Amateur Telescope Makers List <atm.atmlist.net>
List-Post: <mailto:atm@atmlist.net>
List-Subscribe: <http://www.atmlist.net/mailman/listinfo.cgi/atm>,<mailto:atm-request@atmlist.net?subject=subscribe>
List-Unsubscribe: <http://www.atmlist.net/mailman/listinfo.cgi/atm>,<mailto:atm-request@atmlist.net?subject=unsubscribe>
References: <9.353451d1.2eac1113@aol.com>
Sender: atm-bounces@atmlist.net
User-Agent: Mutt/1.5.6i

Don,

On  0, DHA352@aol.com wrote:
> Has anyone tried an off-centered mirror?  I will try to explain:   Imagine a 
> 22 inch f/6 Newtonian, mask it down to 10 inches.  Now move the  mask near to 
> an edge such that the shadow from the secondary and its support is  not on the 
> mirror.  Now the hard part (thus my question), make only the  unmasked 
> portion of the mirror.  Voila, an unobstructed scope without  astigmatism.  The 
> "Center" for COC grinding would be 2 inches off  the  glass. etc.

This type of telescope is known as a schiefspiegler, see

http://www.seds.org/~spider/scopes/schief.html

By the way, "schief" is a German word meaning "inclined" and Spiegel is
German for mirror.


HTH, Wouter van Reeven

-- 

Black holes are where God is dividing by zero.
_______________________________________________
ATM mailing list http://www.atmlist.net/

References:
- [ATM] Off-centered Mirrors?
  - From: DHA352@aol.com

Prev by Author: Re: [ATM] Re: Lubricating a worm-with what?
Prev by thread: [ATM] Off-centered Mirrors?
Next by thread: Re: [ATM] Off-centered Mirrors?
Index(es):
- Author
- Thread