Edmund Sci 3-d image device

[elliotb@xxxxxxxxxxxxx (Elliot M Burke )]

I saw a few messages about this, and since I knew its inventor, thought 
that a few words about it would be in order.  This is an example of a 
real, as oppposed to a virtual image.  There are two very fast 
parabolas facing each other.  The object is at the focus of the top 
parabola, which is facing down, collimating its image.  A second 
parabola below the first, facing up, forms a real image ( at its focus) 
the same size as the original (since the parabolas have the same focal 
length).
One of the nice things about twin parabola systems like this is that 
they are corrected for all aberrations except field curvature.  This is 
unusual for a system of this field size and f/#.

This device works if you view a little away from the axis of the 
parabolas, if on axis you don't look at the mirror's image, but at the 
object itself.

You can make a real image with a large aperture lens by placing an 
object two focal lengths from the lens, the image will then be formed 
two focal lengths on the other side of the lens.  You can view this 
image from different viewpoints and otherwise amuse yourself.


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