[photo-3d] stereoview without viewer or glasses?

["Michael Galazin" <rexlion22@xxxxxxxxxxxxx>]

Has anyone ever come up with a way to put a stereo image onto a screen or
other surface which can be viewed without a viewer up against the face,
without glasses, just viewed simply by looking at it from somewhat varying
distances?

If not, does anyone have any ideas, theoretically, about how it might be
accomplished?  Does some type of selectively refracting translucent material
exist, perhaps?

I can recall seeing a slide projection viewer somewhere, it sort of
projected the view onto a small screen that was an integral part of the
viewer (like a rear projection TV, but this screen was only perhaps 5" or 6"
across).  I don't remember if it was a stereo slide viewer or not.  But you
could either sit close by or stand some distance away, I think, and still
see it.  Maybe someone knows what I'm describing.  If this is a stereo slide
unit, I'd sure like to know more about it.

Cordially,

Mike Galazin