P3D Re: What is the "Stereo-Base"?

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

Bruce Springsteen has attempted to summarize previous "debate" in 
photo-3d regarding the issue of stereo-base, etc. 

>> What is the "stereo-Base"?
>The cause of a great deal of debate, sir!

Actually, from my point of view, the cause of the debate was someone's 
attempt to shove down our throat his idea of the *optimum* stereo base.  
To tell us what is right and what is wrong.  The debate was not about  
definitions or formulas but about the importance and application of the 
formulas.

>1.  You do *not* need stereo base equations to make good stereo
>pictures.  At least not in the vast, vast majority of situations.

Equations relate cause and effect.  They show limits and boundaries
for technically acceptable pictures.  Within these limits there is
an infinite number of good (and bad) pictures.

>4.  Very many formulas have been suggested to achieve a variety of
>other goals in shooting stereo.  In general, these are of more
>theoretical than practical interest...  Your question C has many good 
>answers, it will take time for you to learn them all.

Formulas are approximations of some kind and the more complicated ones 
are the most accurate (taking into account most variables).  If you 
believe that accurate control of the parallax (or achieving a specific
value, say 1.2 mm, in every shot) is important for your photography
then these formulas are of great practical interest for your situation
and your question has only one correct answer.

My problem is that I don't believe that accurate parallax control
is essential for good stereo photography (only photogrammetry), that's
why I have elected not to use exact & complicated formulas in my 
everyday (for my own enjoyment) stereo photography.   Thus, I agree
with Bruce that your question has many good answers.

George Themelis


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