P3D Re: replies on orthostereo

[bercov@xxxxxxxxxxx (John Bercovitz)]

> Date: Sat, 13 Dec 1997
> From: Peter Abrahams writes:
> ................
> My agenda here was to stir up the pot, but I've learned my lesson & won't
> do it again.  Tele- and micro- photography is not generally concerned with
> ortho qualities, though I'm sure there are examples I'm not thinking of.
> It certainly is interesting to think of reconstructing space in an image on
> those scales.  (Or is a macro that accurately scales all 3 dimensions an
> ortho shot?)

> Date: Sat, 13 Dec 1997
> Larry Berlin writes:
> *****  Finally, something about Ortho that makes sense!!!  Regardless of
> whether the term can be defined in this manner, you've hit on the key issue.
> If we can't define Ortho in this way, then we need a term that describes
> this accurate reconstruction at some scale. Or maybe the term Ortho can be
> expanded to include accurate scaling?

I'm very pleased Peter stirred up the pot!  I hope he does it again and again.

I think ortho is too much of an all-inclusive term and that causes our problems.  
Maybe we ought to do away with it and instead use specific descriptions of 
changes from ortho.  These changes have different effects.  I delineated the 
chief three in an earlier post: toe-in, perspective mismatch, and stereobase 
mismatch.  If you have any of these three things, you don't have ortho but 
saying you don't have ortho doesn't tell which of these things you're talking 
about.  I personally don't have a problem with any of these if they are being 
used purposely and not just because the stereo pair maker didn't have a clue.  
However, sometimes accidents look great so even clueless efforts can be great.

John B


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