Stereo rangefinders?

[T3D Dr. George A. Themelis <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

It occurred to me that the parallax bar, as I described it, works as
a stereo rangefinder.  Bill Ewald, who presented the keynote talk at
the NSA Rochester convention, demonstrated a prototype of one of those
which he built while he was working in Kodak.  I believe that this
prototype is now in the hands of Bill Davis.

Looking through the rangefinder you can see two orange arrows and your 
regular scene.  Fusing the two arrows creates a floating point.  
Ajusting the rangefinder dial you can make the floating point stand 
over a certain subject and then read the distance of the subject from 
your rangefinder dial.

Bill liked to play with rangefinders (they even made a special Kodak
stereo camera for him which had a rangefinder).  He mentioned that the
greatest difficulty in using the rangefinder was for people to understand
that they need to have the floating point _over_ the subject.  Letting
overlap with the subject creates confusion.

I wonder if anyone else has ever heard of a stereo rangefinder.  Seems
like a neat toy for stereo fans like ourselves but I am not sure how
useful would be in practical terms.

George


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