T3D Re: stereo math

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

>What we're looking at is the maximum on-film deviation approach to keeping 
>stereo depth within viewable bounds.  

This is, I believe, the core of misunderstandings in previous P3d
discussions.  The 1.2 mm mofd was elevated from a conventional maximum
to some kind of "optimum", something to be achieved in any stereo pair
recorded with a variable base.

I have been under the impression that this 1.2 mm mofd was a conventional
choice for problem-free projection.  I was not aware of work pointing
to this number as some kind of limit derived experimentally, so I guess I
have some reading to do.  Where are Bob Mannle's postings in P3D?

So, assuming that we agree that 1.2 is some kind of maximum, people will
naturally ask, "what is the minimum, what is the optimum?"  Say, I have 
a specific photographic situation in a close up with well-defined near
and far away objects and want to decide on the stereo base. What things
should I take into account?  I have the formulas to calculate on film
deviation.  Should I aim for the maximum?  What other considerations
will affect this decision?  How about the nature of the object/scene
photographed?  The viewing conditions?  Is the question of "optimum
stereo base" purely subjective?  Is trial and error the way to go?

George Themelis


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