P3D Re digest 2801 and 2803 Coke Bottle Cap Mouse Pad

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

Ralph Johnston wrote
"I bought a 3-d mouse pad from the Micro center in Cambridge,MA. it is the
normal 1/8" thick but apears to be about 3/4" thick. The bottle caps are on
the surface suspended over diagonal black & white stripes. I can't figure
how it is done. Anyone? "

To which Bob Maxey replied

"There are a number of decorative plastics used for this process- or at
least a similar process. The ones I am familiar with, will caused objects
placed on their surfaces to sink into or extend or extend out and away from
the surface. This includes printing or physical objects. The materials have
a Lenticular surface but are not Lenticular photography."

"I use these plastics for signs and graphics and the optical effect is
quite amazing to look at"

 To me the description sounds as if it could be a lenticular stereo
photograph or even a hologram as I dont suppose the bottle caps are actualy
on the surface or it would be no use as a mouse pad. But I was interested
in what Bob Maxey described although I can not see how it works with an
object placed on the surface unless it is actualy some sort of lenticular
or Fresnel mirror. Would it not have to be behind the plastic ?. This
reminds me of a badge I saw years ago which had a flat coloured pattern but
which seemed to be set some distance below the surface. It seemed to
incorporate a conventional lens presumably plano-convex into the badge
which produced a virtual image of the pattern some way beyond its actual
position. Presumably at the distance of minimum distinct vision of 20 t0 25
cm as is supposed to be normal for virtual images. But I have never been
able to reproduce the effect myself with any lens ,however its done I
suppose its possible to make a Fresnel lens equivalent consisting of
concentric lenticular lines to do this on a larger scale.     P.J.Homer



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End of PHOTO-3D Digest 2808
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