T3D Re: Advice sought on home-made beam splitter

[bercov@xxxxxxxxxxx (John Bercovitz)]

If you're using a 4x5, you can take one picture at a time and
shift the lens and back in between shots.  But that's only for
still subjects.

I would think a beam splitter for any camera would do as long 
as it has the coverage you need for the format.  All a beamsplitter
does is take the right view and send it through the lens at an
angle so it ends up on the left side of the film as it sits in the
camera.  And vice versa for the left view.

Don't worry about aperture.  To get the same depth of field, you 
use the same aperture (-not- relative aperture) so I don't think
you'll have a vignetting problem.

Of course sending a view through the lens at an agnle generates a 
little bit of a problem inasmuch as this is equivalent to toeing in 
which causes hyperbolic distortion of the reconstructed 3-space.  
However, that's only really noticeable in near objects.

Anyhow, definitely worth a shot.  Take your 4x5 to the camera swap
meet and hold a beam splitter up to it and see if you get good even
coverage of your film plane.

John B


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End of TECH-3D Digest 506
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