P3D Re: One-eyed Hollywood

[aifxtony@xxxxxxx (Tony Alderson)]

Marvin Jones wrote:
<< Which brings us back around to the recurring factoid that three Hollywood
directors who made 3D movies in the early fifties had only one eye (one eye
EACH, that is). Andre de Toth, Raoul Walsh, and Herb Strock could none of
them see in depth! >>

And Jim Norman wrote:
>Don't be so sure that none could see in depth. I recall reading in a
>medical journal some time agao (sorry I can't be more precise) of
>instances in which one-eyed people achieve depth perception by subtle
>side-to-side head movements, with the brain accommodating itself to retain
>the sequential images and combine them into a perception of depth as
>effectively as two-eyed people.

I have observed this behavior more than once in friends who are blind in
one eye.  It was especially marked in one of my high school buddies. I
think there is some connection between motion parallax and stereopsis; this
seems to have been demonstrated by the Visidep process (yeah, it's a goofy
process, but it does demonstrate something interesting about vision.)
Anyway, my observation of my monocular friends is that their depth
perception is not as good as the rest of us, although it appears to be
usually good enough.  Not that I've made any kind of scientifically valid
study!

Jim concluded:
>I don't know whether any of the three directors could see in depth or not,
>but it would surprise me if they could not.

I think we need to distinguish between depth perception and stereopsis.
Clearly none of these directors could see stereoscopically, even though
they probably could construct a mental image of depth relationships from
other cues.

And Bob Maxey asked:
>Finally, I must ask this question: Is stereoscopic vision required to get
>by in life? I mean, one eyed people can drive.

No, stereopsis is not a survival imperative. It clearly, however, gave our
ancestors a marginal survival increase, which may have been very
significant in the long run for our species.  Sure, one-eyed people can
drive and live happy lives. Stereopsis just allows us to judge distances
more quickly and accurately than would be possible without.  That probably
makes a big difference for wild animals, and even for a few humans today.
I'm sure you can cite one-eyed race car drivers, but I'd guess stereopsis
makes the job easier and safer.

As for myself, I'm somewhat hearing impaired, so the other discussion of
stereophony and stereoscopy struck me as comical and ironic all around!

Yours in depth (but without high-frequencies)
Tony Alderson



------------------------------