P3D Re: Stereo Nomenclature 2000

[Larry Berlin <lberlin@xxxxxxxxx>]

> Date: Tue, 18 Jan 2000 
> From: Bruce Springsteen <bsspringsteen@xxxxxxxxx>
> .............
> .... What DOES surprise Bruce is that his own
> lengthy and presumptuous assault on a central question of stereoscopic
> matters - the meaning of orthostereo - has yielded so little debate of any
> kind, thusfar.  .........
> .....   (I know, but I dream big dreams - and my definition of ortho
> lies only in the objective space of geometry, before the brain comes into
> play - I concede that the brain will play havoc with perspective, but we
> must measure things anyway!)
> 
> Is my argument too foolish for attention?  Or too sound for rebuttal?
> Can none of you good gentlemen spare a drop of your bile for me?  I
> thirst...
> 
> Bruce (the Patient Masochist) Springsteen
> 


Hi Bruce,

How can your definition depend solely on objective space geometry? Is it
not 
the perceptions of the brain that we end up measuring as ortho or not?
The 
problem becomes how to get a ruler inside the brain to measure things!

Even Ortho depends on perspective factors. Take the often used cubic
illustration. 

How much perspective effect exists depends on how close your observation
point is to the 
cube. Thus for each observation location, the (averaged human)
perception defines what 
is ortho from there. Notice too that the closer you get to the cube, the
wider your 
fixed base becomes relative to your distance. Yet if that's where you
viewed the 
cube from, that's the perspective that is defined by ortho, simply
because your eyes 
remain the same distance apart. (What would they do about defining Ortho
if our eyes were 
on stalks like some crab's?)

Yet when one applies a wider base than the eyes to a view of something
the size of a house, 
suddenly the taking/viewing geometry is breaking the ortho rule, even if
the results are 
completely 100% scalable to the -ortho- close-up of the cube.

Your proposals about Ortho might resolve such paradoxes. Yet the same
question 
can be asked of you that was asked of me. Since the issue in question is
somewhat 
widely used, what good does it do to more correctly define the term
now?  ;-)

Without attempting to define why, I think it's worth it. 
-- 
Larry Berlin

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lberlin@xxxxxxxxx
http://3dzine.simplenet.com
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