P3D Re A technology question digest 2825

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

The thread on holography seems to have run its course now but Bryan
Willmans original question in digest 2825 was whether holography could be
used to display a stereo pair. I remembered reading something like this and
cheked my local library at the weekend. The "Manual of practical
Holography" has a section on two or more channel holograms, these are the
ones which switch to a diferent view or views as you tilt them. Often an
interior/exterior view I have some by the polaroid corporation of an
anatomical model of a head which switches to an internal view of the brain.
In the mid position you get a combined view as one eye sees each image,
this can be used to display a stereo pair . To make a two channnel hologram
first two holograms one of each view needs to be made with an identical
optical set up. For as stereo pair this is of each one of the pair they are
then sandwiched together while viewed with the laser to get them in exact
registration and taped together temporarily. They should then be cut up the
middle with a guillotine and then the left and right halves of the two
different originals butted together and used as masters to record a second
transfer hologram from the real image of the originals produced by a more
diverged laser beam. This seems to make use of the ability of just part of
a hologram  to reproduce the whole scene although with reduced parrallax
.Each image will give the whole of one half of the stereo pair and in a mid
position each eye will see just its respective half of the stereo pair.
P.J.Homer



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