P3D Re: Realist mounting and the "stereo window"

[Paul Talbot <ptww@xxxxxxxxx>]

Dr. George A. Themelis wrote:
 
> Yes, indeed... simple geometry can be used to reproduce 3-d space and
> reconstruct the stereo window [snip] One problem however is relating
> these geometrical figures with real-life experience and stereo
> perception.  There are people (and I believe Paul Talbot
> is one of them - per earlier P3d postings) who do not perceive
> the stereo window set at 7 ft. (or whatever) from the camera.

Actually, what I've indicated is that I do not get a life-like
experience of the window as percieved through the *viewer* to
be at distance of 7 feet from my eyes.  To me, that is quite
different from the above paraphrasing of my comments.

The formula tells us what point along the z-axis the window occurs.
If the formula results in a distance of Z feet, we can then state
that objects in the scene that were less than Z feet from the
shooting reference point* will be perceived to be in front of the
window; and objects more than Z feet will be perceived to be behind
the window.  When viewing a slide with a window at 7 feet, I do see
objects 6 feet distant as in front of the window and objects at 8
feet as behind the window, as it should be.  However, I have the
perception of viewing a reproduction of the scene in a slide
viewer, not the perception of seeing real objects in front of
and behind a real window 7 feet away.

I hope the distinction is clear.  I'm sure the words could be better.

*I say "shooting reference point," as opposed to "the camera" or
"the film plane."  I think John B has indicated the reference point
is actually the "entrance pupil" of the lenses, or something like
that.  Too technical for me, however.  :)

Paul Talbot


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