Re: [ATM] Lens after diagonal?

[Michael Lindner <mikell@optonline.net>]

On Wednesday 25 August 2004 02:32 pm, GARY FUCHS wrote:
> Place a lens immediately alongside a much smaller than usual
> diagonal so that the cone of light, hitting the diagonal at
> appproximately focus, would be refocused to a point
> comfortably outside the tube.

This is called a "relay" or "transfer" lens system, and usually consists of 2 
positive lenses spaced apart by their focal length. There was an article on 
it in S&T a couple of years ago - perhaps someone has the reference handy...

There are scopes, like the Dilworth Relay telescope, which use something like 
this as an integral part of the design:

http://www.atm-workshop.com/dilworth.html

-- 
Michael Lindner
http://www.starastronomy.org *** http://home.att.net/~mikel
http://www.atmsite.org *** http://www.atmlist.net

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