T3D Re: stereo math

[Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 7:16 AM -0700 9/15/98, Tom Deering wrote:
>
>I visualize 1.2mm of onfilm deviation as being related to the amount of
>convergence the eyes can comfortably do.  Would it be just as correct to
>measure it as an angle?  And is that why the 1.2 mm is actually f/30?
>

Actually, it's a function of the fusional range of the visual system, i.e.
the amount of disparity (difference in position of a feature between the
two eyes' images) that the brain can merge into a single image.  Which in
turn is a function of the maximum spacing between locations on the two
retinas from which neurons in primary visual cortex take their inputs.  To
oversimplify  :-).

As I think Boris pointed out on that other list, it may also be affected by
the magnitude of the disparity gradient.

-Jim C.
----------------------
Jim Crowell
Caltech Division of Biology
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