Re: simple do-it-yourself 3d movies?

[P3D Gregory J. Wageman <gjw@xxxxxxxxxx>]

>Rig a stand to hold the
>beam-splitter in from of the projector lens.  Put polarizing filters in
>front of the beam-splitter.  Adjust the outside mirrors on the
>beam-splitter so the split images are correctly superimposed on the
>screen.  Put on polarized glasses.  Enjoy.  Can anyone see the flaw in
>this plan?

The problems that I see are all optical in nature.  Remember that during
projection, the image starts out *very* small, and expands on the way to
the screen.  If the beamsplitter is close enough to the lens so that none
of the image is cut off by the rear aperture, the separation between
the first pair of mirrors will probably be too large, and you'll lose the
center of both images.

As you move the splitter away from the projection lens, you'll lose less
at the centers, but then the aperture may become to small.

Mind you, this is all from the gut and could be entirely wrong.  Certainly
an experiment would be worthwhile.  (I've been planning to try something
like this with videotape and a mirror/real-beamsplitter combo on the TV
for playback.)

        -Greg W.


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