Re: Why 3D (convergence as a depth cue)

[P3D Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 10:51 PM -0700 6/16/97, P3D  Dr. George A. Themelis wrote:
>>If I'm in a very dark room, with just a point source of light
>>in my field of view, I can make a very accurate estimate of the distance
>>from my eyes to the light source, with convergence as the only depth cue
>
>Have you tried this?  How did you recreate the light point source?
>Could it be that you used a source with a known finite size and you
>were judging distances based on this size?  Did the light source
>move or was it stationary?  I believe you would be at a loss in
>estimating the distance of a fixed light point source.
>

Don't forget accommodation (or for old-timers, the fixed amount of de-focus
present  :-)   )....crude but important

I agree, the evidence suggests that people aren't very good at this.

-Jim C.

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Jim Crowell
Caltech Division of Biology
216-76
Pasadena, CA
Tel: (818) 395-8337
Fax: (818) 795-2397
jim@xxxxxxxxxxxxxxx



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