3-D an illusion? Certainly not!

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

I am often amused and sometimes annoyed by those who call stereo an
illusion.  So, I created a slide to demonstrate that 2D is an illusion
instead.  This is part of my "scientific" 3D talk.

I took a picture of a metal cup (from work) that was tested by dropping a
weight at the open end and has cracks in the walls.  I took pictures of it
looking straight down.  The 2D picture looks like the cup was ran over by a
track.  Totally flat.  The 3D picture shows that this is still a cup with
cracks, just as the real thing.  

When I show these two pictures I emphasize that the 2D is an illusion
because it gives you the wrong qualitative and quantitative impression.  3D
is the next best thing to "being there" and seeing the object with your
eyes.

Of course, I "cheated".  First, I recorded the picture looking straight
down which is the least favorable angle for 2D photography. Had I taken the
picture at an angle, it would have been clear that this is indeed a cup
with cracks, even in the 2D picture.  Sometimes we have no control over the
angle of view.  But most times we do and (flat) photographers know that
certain viewing and lighting angles will emphasize the form and shape
better than others.

Second, I mounted the 2D picture by having the object right at window
level, or even a little tiny bit forward.  This way I eliminate the extra
sense of depth from having a (flat) picture behind the window.  I did this
with all the comparison flat pictures.  I had some flat pictures of
diagrams that I was not comparing with 3d pictures.  These I mounted
slightly behind the window for extra depth.  I love the control of depth
impression through mounting w/respect to the stereo window!!!

George Themelis


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