Stereo Intro slides

[P3D KENNETH LUKER <KLUKER@xxxxxxxxxxxxxxxxxxxxxxx>]

I've just mounted seven slides that I intend to use when I'm showing
newbies or potential recruits some of the basics of stereo
photography.  I went into the new Eccles Center for Human Genetics
where a seven-storey staircase rises diagonally throught the
seven-storey atrium and across the windowed face of the ultra-modern
research center, highlighted by stainless steel balustrades and
angled stair landings.  It is quite spectacular. 

I shot three identical stereo pairs from the bottom looking diagonally 
upward along the stairway.  I then went to the top level and shot 
one view looking downward along the stairway.  On the top level there 
was a lounge room with a full open view of the Wasatch Front, the 
mountains south and east of Salt Lake City.  I shot three identical 
stereo views out the window, with the lounge chairs in the foreground 
and the morning-lighted mountains in the background at infinity.  

I mounted the Left-eye view from two of the staircase shots into a 
single mask, one at the left and one at the right, but placed the 
stereo window exactly at the film plane.  When viewed, the slide 
looks just like a normal flattie slide, except that it is seen with 
both eyes.  I took the corresponding two Right-eye views and mounted 
them in a second mask, but this time, I offset the two views by 
separating them slightly, so the flattie picture appears to be 
significantly on the far side of the resulting stereo window.  
Finally, I took the third view and mounted it as a normal stereo 
shot, with the near baluster at the window, and the rising layers of 
staircase moving backward and upward in true stereo.  

I repeated the mounting techniques with the three shots of the 
mountains outside the window: one with two left views mounted at the 
same separation as the mast openings so there is no separation 
between the frame and the view (no stereo window); the second with 
the entire view still flat but definitely beyond the now-obvious 
stereo window, and the third in true stereo.

This is how I'll use the views:  
1. Show the first stairway flatty.  Nice composition, but nothing 
different than a flatty photographer would shoot with a single lens.
2. Show the second stairway flatty:  Now it is apparent what DEPTH 
means:  the picture is definitely beyond the frame.  Explain the 
concept of stereo window, if the audience is appropriate.  Point out 
that the picture is still flat.  Suggest the concept of nailing the 
distant point in the second picture to the back wall, and stretching 
the near points toward the viewer to give depth WITHIN the picture.  
3. Show the third stairway picture--in true stereo.  Voila--the 
concept is obvious, and converts flock to the next club meeting.

4.  Show the three mountain/window shots in the same way.  The points 
are re-affirmed until the stereo shot is shown.  Oh, oh.  NO STEREO 
in the distance!  It is clear that the window and lounge chairs are 
in three dimensions, but the mountains look like a poster plastered 
on a wall outside the building.  The loss of true stereo vision 
beyond a reasonably near distance becomes obvious, and again, 
depending on the audience, a good discussion could ensue.

5.  Oh, the last stairway picture, taken from the top of the stairs?  
I mount that upside down and pseudo-stereo.  What a BLAST to the 
vision.  Things are hardly recognizable.  I can explain the concept 
of pseudo stereo and special effects.  Then, to put the icing on the 
cake, I turn the pseudo-stereo picture upside right and have the 
people take off their glasses, rotate them forward to the upside down 
position with the ear-pieces pointing to the screen and look again.  
Voila- the picture has become a great, normal stereo picture of the 
staircase from the top.  

Comments?
Ken Luker
_______________________________________________________________
Kenneth Luker
Marriott Library Systems and Technical Services
KLUKER@xxxxxxxxxxxxxxxx


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