Re: [ATM] Off-axis Newt

["stU" <stu@aaronj.com>]

Bob,

I am converting 2  Meade 114NT f8 Newtonians into a binoscope.
A binoscope requires that the eyepieces be in line with the tubes.

The secondary may need to be closer to the primary if the mirror/diagonal
extends the focal point too much.  In that case, the secondary becomes
larger, and blah, blah......

I was also thing the "What if?" in regards to an off axis secondary.

If you could achieve an off axis secondary and a mirror whose combination
would achieve a parallel eyepiece axis, you would have a winning binoscope
design.

Wanna try it first with my pair of 114's?

Stu 


-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
The Alarm Co.
Sent: Friday, January 27, 2006 7:09 PM
To: ATM List
Subject: [ATM] Off-axis Newt

After following several links from recent discussions here, I'm just about
convinced I can make a good toroidal mirror.  So, I'm now contemplating
converting my 16" f/5.4 Dob into an unobstructed scope.  I've seen several
examples of replacing the centered flat secondary with an off-axis toroidal
secondary, but no general method for determining the prescription for a
toroidal secondary to match a given paraboloidal primary.  Any ideas?

 *  Best regards, Bob
*
         *           *   *

            *         *


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