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From: daw1@mhuxl.UUCP (WILLIAMS)
Newsgroups: net.sci,net.rec.photo
Subject: Re: 3D picture on cover of National Geographic
Message-ID: <342@mhuxl.UUCP>
Date: Wed, 20-Nov-85 22:29:41 EST
Article-I.D.: mhuxl.342
Posted: Wed Nov 20 22:29:41 1985
Date-Received: Sat, 23-Nov-85 00:05:43 EST
References: <547@scirtp.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 23
Xref: watmath net.sci:469 net.rec.photo:1640

> The cover of the latest National Geographic is a 3D picture of
> a skull, and when it's held in the light at the proper angle
> the 3D effect is startling.  I know that such pictures are made
> with lasers, but what is the process?  Also, how are these
> pictures mass reproduced?  The picture on the magazine looks like
> silver paper with some black substance on it.  Or is the "black
> substance" really an etching of some kind?

	Laser hologram is the name of the process. About a year
or so ago they had an eagle or something on the cover that used this
technique and an article inside explaining the process. Check it
out. Also, try Disney World in Florida's Haunted Castle for *moving*
holograms: ghosts float around and as the ride is about to exit
there is a mirror on the wall so you can see the ghost sitting on your
shoulder! Wow, it's neat stuff.

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