P3D Bruce's Challenge - IV

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

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.

Regarding the effect of B only, there have been a few examples in
the literature.  The most effective use of varying the B is the so
called "space control" in various 3d illusions.  By changing the 
distance of the subject from the camera (I) and the stereo base (B)
you can make it appear in any location and in any size you desire.
Examples of illusions include the lady inside the glass and the 
artist who is painting a live model in his canvas (see Tommy Thomas'
chapter "Stereolusions" in "The Stereo Realist Manual".)

Ted Lambert has created a stereo pair with triple exposure, featuring
a tabletop figure recorded with three different stereo bases in the
same picture!  (This can be seen in my Realist book, page 75, Fig. 
7.21)  In 3d it appears that each figure is located at different
distances from the observer and has a different size, with the 
closest one appearing the smallest.  Freeviewing this pair in the
book is not as effect as showing it in projection.  In projection
I ask people to take their glasses off and confirm that the 3 figures
have the same size.  Most people refuse to believe this until they
see it with their own eyes.  It is fascinating!!!

So, Bruce, what do you think?

George Themelis
DrT-3d@xxxxxxx