P3D Re: Non-stereo depth cues (2506)

[JNorman805 <JNorman805@xxxxxxx>]

In P3d digest 3506, Bob W. writes:

<< I recall at the NSA convention in San Antonio years ago at one of the
 theater showings that the presenter said that if he had people in an
 audience who'd never seen stereo slides before, he had a little trick.
 
 He'd have 3 copies of the same view. One would be just a normal flat
 view (one eye). The second would be the same one image, but positioned
 with a little displacement so it appeared to be behind the window - that
 got oohs and ahhhs. Then he put the same slide up with both images and
 it blew people right out of their seats (he said) >>

I had a similar experience last Monday night, when I put on a modest stereo
slide show at the Westchester Color Camera Club.  I showed a series of four
pairs of slides of the same view, a cityscape shot from the 63d floor of the
Chrysler Building, looking north.  The first pair was my "normal"  stereo
base, about 3 3/8 inches, dictated by the physical limitation of my bottom-to-
bottom twin SLR rig.  It looked entirely flat.  The second used a stereo base
of about 7 feet, which showed considerable stereo effect.  The third, which
elicited the oohs and aahs we all live for, used a base of about 15 feet.
Then, just for fun, I made a side trip into Escher-land, and showed the group
the same wide-base shot, but in pseudostereo.  Switching back and forth
between the true and the pseudo shot several times sparked some lively
reaction.  
                       Jim Norman    


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