Archived posting to the Leica Users Group, 2002/11/19

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Subject: RE: [Leica] Get out the Leicas - Leonids tonight
From: John Bohner <johnbohner@earthlink.net>
Date: Tue, 19 Nov 2002 20:44:37 -0800

BDColen Wrote

>Don't you love that, Nathan? (The people taking flash photos of Halley's
>comet). It's almost as hopelessly dumb as the people at stadium rock
>concerts snapping away with their point and shoots with flash...Boy,
>would I like a flash I could control with, say, 150 yard range...:-)

Actually ,you sort of can get 150 yards out of your strobe.
Long ago and in a jurisdiction far from here, two Physics majors at a large
US university,  with time and equipment on their hands did an odd optics
project.  They thought it would be interesting to see what kind of
projected pattern one would get by firing a strobe out backwards optically,
from the focal point of an 8 inch diameter Schmidt-Cassegrain telescope.
Answer, a pretty bright spot at even a 1/4 mile.  Next they put said
contraption on a hill top dormitory roof, at night, and randomly
illuminated campus police sitting in their cars around the campus. They
campus police would dash off, lights ablaze and then stop to regroup. It
was a bit like using a laser point to play with a cat except the cat is
usually smarter. Great fun but the physics majors sobered up and went to
bed.  

So one could buy two  APO-TELYT-R  f/5.6/800 mm lenses, mount them in
parallel, put an R9 on one and the strobe behind the other.  The rest is
left as an exercise for a well-to-do student.

John B 
Suos Cultores Scientia Coronat



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