P3D Re: 2D/3D

[Greg Erker <erker@xxxxxxxxxxxxxx>]

>>  Also, in a hologram you have to focus at
>different depths to see the image that appears
>to be at that depth. This is quite unlike a
>stereo slide where you have to uncouple the
>focusing of your eyes (focus at a fixed distance)
>while you view objects in the scene that appear
>to be at different depths.
>
>When you look at a stereo slide your eyes refocus to see objects at
>differing distances. You can hunt around in a slide to pick out
>different objects.

  If you project a stereo slide and sit
3 feet from the screen your eyes will
be focusing at 3 feet no matter where
you look in the scene (depth-wise), otherwise
the image will be blurry.

  You do see depth due to the different
amount of converging your eyes do to
view objects at different depths but your
eyes stay focused at the screen depth.

  If you view a transmission hologram with
a magnifying glass you actually have to
move the magnifier in and out to refocus
on parts of the scene at different depths.

Greg E (former holographer, present stereographer)


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