Two Image Lenticulars

[P3D <LeRoyDDD@xxxxxxx>]

Larry Berlin writes and [I respond]:

"You have to think of lenticulars as lenses."
     [In the sense that the lenticules 'project' to each eye the correct
stereo view behind the lenticular screen for that eye. Previous barrier
methods used an opaque line screen to prevent one eye from seeing the view
intended for the other eye. Both systems are dependent on the geometry of the
screen, images and viewer.]

"A single stereo pair does contain the necessary information but not the
inbetween vantage points which is needed with the lenticular. With an
ordinary stereo pair you can slide your eyes to any and all of the possible
angles of view."
     [Would this were so! A single stereo pair records only one angle of
view.]

"In a lenticular, all those variations have to be present at the many places
the lens focuses your attention. These places don't always coincide with
where it's located for a single pair of images."
     [Actually, the varying points of view are only present at those places
where there is a single pair appropriately placed in accordance with the
geometry of the system.]

"The idea of viewing it from one angle presupposes that the material itself
provides different angles ranging from that very narrowly defined vantage
point. In reality a lenticular viewed from a very carefully stationery point
requires a number of sets of different pairs, which are made available at the
different angles. In other words, the lines of coincident pairs from a fixed
viewpoint are not parallel to each other."
     [I'm not sure if I understand this, but the idea that a lenticular
viewing system requires more than one set of stereo pairs is not true.
Differing geometry of the any lenticular system provides the stereo pair
"positions" unique to that defining geometry.
     I think the # of pairs is N minus one where N is the # of single images
available behind the screen.
     So a four image system(Nimslo) has three separate stereo views
available, three image systems have two(ImageTech). Each image doesn't have
to be in stereo, as in animation lenticulars, or they could be the same
image, which would be boring to most of us.]

     The original question to which Larry was responding seemed to ask, "Can
I get a lenticular from just two images?" I don't know of a system that has
it's geometry set up for that, but it would be possible.
     If you get your Realist(or any stereo pair) images on a Nimslo negative
in the order, LLRR, you could get a "Realist" lenticular print with a stereo
pair in the center viewing position and two flat images in the outside
viewing positions.

     LLRR, in a four image lenticular system has only one half the resolution
of LR in the hypothetical two image lenticular system, but that's another
discussion.

     I may have misunderstood both the questions and the answers(happens in
real, non-photo 3-D life, too :=)). Lenticular stuff can be confusing to
me... after I figure it out, totally, I'll move on to SL3D!

LeRoy Barco
LeRoyDDD@xxxxxxx


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