P3D Re beam splitters

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

Mark shiels Wrote in reply to Nathans posting

>
>I have heard of people experimenting with attaching a beamsplitter
>to a movie camera. You need to have manual control over the aperture,
>or you will get either image overlapping or a wide black band between
>images. For projection, you have to set up two front-surface mirrors
>so that the projected light will bounce off them, each at a slightly
>different angle, to superimpose the images on the screen. There have
>to be special polarizers installed in the projector to polarize each
>image differently. Then, since it's a movie and you can't turn the
>film around like you can a slide in a slide projector, to unreverse
>the images, you would need _another_ mirror to accomplish that.

I think the projection version of the Stereo-Tach or something like that
used the simple method of just two mirror surfaces for projection ,I dont
know how the reversal problem was solved. It should even be possible to
project just one half of a pair off a mirror so as to overlap with the
other half but then one image would have to reversed on the film with
respect to the other. Some beamsplitters such as the Stitz could also be
used for projection and the second reversal in the second mirror corrected
the image.  P.J.Homer



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