Re: [ATM] lensmaker for a very long focus objective

[Michael Lindner <mikell@optonline.net>]

On Friday 26 March 2004 12:09 am, Peter Abrahams wrote:
> The aerial telescope idea is an extension of this thought. It's an
> attention-getter, an "attractor" in museum-speak, something that will bring
> people over to see what it is.

This is a wonderful thought.

> We will attach the objective to a flagpole or something. An existing pole
> is 100' from a likely viewing area, so I suggested an objective with 100'
> focal length.

However, a flagpole bends in the wind. Without something to keep the two 
components (objective and eyepiece) a fixed distance from and square to each 
other, viewing would be impossible. A 1 degree tilt of the objective would 
result in the focal plane moving about 1.5' to the side!

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

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