P3D Re: barrier samples review

["ZEXIAN SHEN" <z.shen@xxxxxxxxxxxxxxxx>]

>------------------------------
>
>Date: Wed, 2 Dec 1998 18:41:24 -0800
>From: aifxtony@xxxxxxx (Tony Alderson)
>To: photo-3d@xxxxxxxxxxxxxxxxx
>Subject: P3D Re: barrier grid review
>Message-ID: <v01520d04b28baa688890@[209.141.84.36]>
>
>John R (digest 3093) wrote:
>>(...) I believe lenticular and barrier strip-type displays are usually
>>made with a particular interocular in mind. (...)<
>
>Not exactly. Autostereos are designed to a particular viewing distance for
>the average interocular. Persons with narrower spacing will find the "sweet
>spot" a little closer, persons with wider spacing will find it a little
>further back. (Think about the angles from a "top" view.)
>
>I just got a chance to see two of Jason Shen's barrier strip images over at
>Ray Zones'; the two tigers and the pool room. They strike me as pretty good
>examples of the art.  The viewing distance seems to be about 6-7 feet. In
>my opinion, this is a little far back for images of this size (about a foot
>square), but I realize that can be adjusted. One thing I notice is that
>barrier strip images are significantly sharper and contrastier than
>lenticulars, this improves the impact.
>
>It's clear there are parallax limits to autostereos, but as far as I can
>tell, practitioners determine this by trial and error, or just hope for the
>best. If Shen's pool room image had a little less parallax, the image
>doubling at the far range would not occur, and the slight loss of depth
>would not be noticed, probably improving the effect overall. It might be
>helpful to have something like MAOFD for autostereos. I have never seen
>such an analysis published, and haven't been sufficiently motivated to
>apply my limited intellect to the problem. This is a multilevel problem:
>first one has to determine the limits for a given barrier or lens, then
>figure out out to get that into the image array.  But that is a topic for
>Tech 3D.
>
>Anyway, I would be interested in hearing how the tigers were photographed.
>I seem to recall Jason saying he is using a rail camera, how the heck did
>you prevent the animals from following the motion of the camera? Was this
>done some other way?
>
>Tony Alderson
>aifxtony@xxxxxxx
>www.aifx.com
>
>>***************************
 I totally agree Tony's opinions.

Autostereos have some small limitations but solve the big communication
problems of the tranditional steregraphs. That is, when the weakness of
double images could be ignored by common sense, the autostereos could
communicate good images in a large scale as the 2 D photos do. However, the
2 D photos can never reach the 3rd dimension. Therefore, as far as our
recent technology, the advantages of barrier are much more than its
disadvantages.

 The stereo slide can not solve the communication problem so that can not be
commercialized in many markets, so that it is only for children use. If the
stereo professionals are still involved only in the traditional
stereographs, they will never possibly beat their 2 D professionals.

Tony: the "tiger" photo was shot by the 5 lens of professional camera. Our
photographer waited in the Zoo for the tigers going out over 10 hours. If I
had known your computer could process 2 D to 3 D earlier, he would not have
had to waite so hard.

Jason Shen
Fiso Stereographs Inc.




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