Two Image Lenticulars

[P3D Bill Stratemeyer <wwstrat@xxxxxxxx>]

LeRoy Barco Posted and [I respond]

>> Larry Berlin writes and [I respond]:
>>
>>"You have to think of Lenticular's as lenses."
>>     [In the sense that the Lenticular 'project' to each eye the correct
>>stereo view behind the Lenticular screen for that eye.
< snip>
>>"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.]

 Isn't that 2 angles 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."
<SNIP>
>> "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.
<SNIP>
>      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.

 
  Yes you have the text book explanation of how Lenticular's work then
there's  
the real world. ;-) ;-) Let's greatly exaggerate the situation so we can 
visualize what's happening, Think first of a Lenticular print that is 3D
and
1" wide, everything the left eye sees is right of your left pupil, call
this a 
positive angle. Now enlarge this same print to 10' wide and viewed from
the same distance, your left eye will see app 40% of the print at a
negative angle( left of the left eye) the same views as the right eye's
positive views. So the angle of view 
across the print, displays a mix of several stereo pairs. This is one of
the reasons
you may be dissatisfied when you get your favorite 5"x7" enlarged. There
are several other factors that contribute to scintillation and loss of
depth when you enlarge Lenticular's.  
 Two image lenticulars are only possiable in very small prints. Larger 2
image prints
result in only seeing depth in a narrow view between your eyes, this is
of course dependant on your viewing distance.


>      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!

  If you figure it out "totally" please fill me in.  ;-}
   
 I Here by nominate Dr-T. As moderator of the sell-3D list.

Actually wouldn't this work better as an unmoderated news group?

..............................................................
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       Bill Stratemeyer .
       1308 E. Libby Dr.,  W.P. Bch. Fla.   33406  
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