Basic newbie question

[P3D Marvin Jones <Campfire@xxxxxxxxxxxxxx>]

Message text written by INTERNET:photo-3d@xxxxxxxxxxxxxxxxxxxxxxxx
>If my question is simplistic you can thrash me but: Why do we see
something resembling a 3D image when two identical images are juxtaposed
and viewed in the crossed modality?<

We don't. The trick word in your question is "identical". The two images
making up a stereo pair are NOT identical. If they were, they would appea=
r
perfectly flat. The point of stereographics is to simulate the views of t=
he
two eyes, which each see a scene from a slightly different angle -- very
slightly, but different nonetheless. It is the differences between the tw=
o
views that the brain interprets as depth cues. In the same way, when we
look at two images that are *ALMOST identical but slightly DIFFERENT* the=

brain interprets the differences as depth. In a nutshell, that's what
stereography is all about.


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