P3D Breaking Holograms is Bad

[John Toeppen <toeppen@xxxxxxxxxxx>]

RE: Dividing up holograms

Eric at Holostar forum wrote this nice description of what's left when
you break a hologram:

 Think of your hologram as a window. Say your about a foot away from
your window and from that distance you
 can see an entire tree about 20 feet on the other side. Now you pull a
shade half way down the window (break the
 hologram in half). You now see half of what you saw before including
about half the tree. But if you get closer to
 the window or you bend down you will be able to see everything you used
to. Whats different? You've lost some
 perspective, the viewing angle is half of what it was. Maybe there was
a bird house on the tree at eye level that you
 could see right into, now since you have to look at it from a lower
point of view, you can still see the whole bird
 house but you've lost the point of view that allowed you to see into
it. If you shade the whole window (hologram)
 and leave a small peephole, you will see almost nothing from a foot
away. But if you position your eye at the
 peephole, you will still see the entire scene. Of course, at this
point, there is no viewing angle left. You can only see
 the scene from one angle. This is the same with a hologram. If you flip
a hologram it will project a real image, if you
 now light it with an undiverged laser beam (about 1 mm diameter) it
will project the entire image. If you then move
 the hologram, the image projected will be shown from different points
of view. You're hologram is now basically 1
 mm in size and yet it still projects the entire image! Of course, you
only have one point of view and you can no
 longer see it in 3D.

 Basically, the whole image is contained at every point of the hologram
but different areas of the hologram record
 different points of view.

 For all this to work, it must be a laser viewable transmission hologram
with the subject being at a distance behind
 the film!
------

For more information and chat on holography heck out the forum at:
http://www.cam.org/~rioux/holostar/index.html


John Toeppen / Holo Graphics
http://home.pacbell.net/toeppen/




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