P3D Re: No Challenge Goes Un-met

[Bruce Springsteen <bsspringsteen@xxxxxxxxx>]

George Themelis never shies from a challenge, and I'm never disappointed
in his analysis:

> So, Bruce has challenged us to show how changing the focal length
> (F) and the stereo base (B), affects the recorded and the perceived 
> stereo image.

(...)

> So, to meet Bruce's challenge I have created a series of stereo pairs
> using my digital camera and a setup with 3 bowling pins at two depth
> levels.  I have recorded the scene under different conditions by 
> varying F, B and I.  All the effects that I described in my previous
> postings are seen in the resulting stereo pairs.  These will be
> published as part of the "Tutorial" I am writing for the "Stereogram"
> and they will appear in issues 4.5, 4.6 and 4.7.  Someone with a web
> page can try and recreate these situation for all of us to see.

This is just what I had in mind.  I guess it's time to subscribe to
"Stereogram".  I will be anxious to see how these images are arrayed for
comparison - it should be called the Themelis Matrix for the Visualation
of Stereo Variables, if it is successful.  Perhaps an online animated
version, even an interactive one where you can change the parameters and
see the changes in real time, will be developed as our University of
Stereography website evolves ;-).  

> Ted Lambert has created a stereo pair with triple exposure, featuring
> a tabletop figure recorded with three different stereo bases in the
> same picture! 

J. Ferwerda has a nice line drawing example of the same principle, with
several blocks in a row that appear the same size and distance until
viewed stereoscopically.  The block sdrawn with greater deviations
suddenly appear nearer and smaller than their neighbors, counter to all
expectation.  As Herbet McKay emphasizes in his discussion of "space
control", parallax (as controlled by base) always determines perceived
distance - overriding
our expectations of size.

> So, Bruce, what do you think?

Please send "Stereogram" subscription info! ;-)

Bruce


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