P3D Re: Holograms

[KenDunkley@xxxxxxx]

In a message dated 98-07-10 11:30:03 EDT,  Bob_Maxey wrote:

<<  What is interesting about a holograph, is that if you take one and cut it
 up into fractional pieces, the entire image can be reconstructed from each
 piece. The image exists at every point in the holographic image.  >>

Actually this is only true for non-image plane holograms.  In an image plane 
hologram a real image of the object being recorded is projected (typically 
by an ordinary lens) onto the hologram recording plate.  Afterwards, during 
reconstruction, the reconstructed 3-D image can be observed to straddle 
the plate,some of it projecting in front of the plate and some behind it.  

The classic example of this is a white light reflection image plane 
hologram.  In these instances the holographic information 
(fringe pattern) is not redundantly recorded. 

If you break the hologram into many pieces, each piece actually 
carries with it a unique portion of the reconstructed image.   
Redundancy turns out to be function of the perpendicular distance 
of the reconstructed portion of the image point from the hologram plate.


Respectfully submitted
Ken Dunkley


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