P3D Re Hollow face Illusion

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

I bought one of these of the Mask of Tutankamun by mail order, originaly I
thought it was going to be a pseudoscopic dichromated gelatin hologram
because it was described a a 3D image. In fact it is actualy 3 dimensional
not an image but the inversion does make it apear to be in front of its
actual position.
 you can get a pseudoscopic image from most holograms by simply using
convergent rather than divergent light or turning the plate around if they
are intended for use with transmitted light or if the backing can be
removed. You can also see a pseudo image if you hold a holgram horizontaly
and view from the bottom at a shallow angle . Turning the hologram from
side to side will then make the image move in the reverse direction and
this will work for incident light holograms where the backing cannot be
removed . I find an inverted depth face looks normal in a stereo pair but
you do not get the affect of it following you as there is now no parrallax
change as there is with a real mask or hologram. P.J.Homer