P3D Re: Apeture when shooting stereo?

["William Carter, Ph.D." <wc@xxxxxxxxxxxx>]

At 12:51 AM 8/7/99 -0600, Bob H uses a broad broom to paint the following:
>RE: Someone told Nathan Kreuter that he should use largest
>opening when shooting stereo? This person was a no-nothing,
<snip>
>  In stereo this is bad advice, since in the viewer when the eye
>wanders around if is offended if it finds an out of focus area (AS
>THE EYE AUTOMATICALLY FOCUSES WHERE IT LOOKS).
>So we choose the f/stop that will keep most of the visible area
>sharp.  (Some may argue that blur and out of focus is artistic..it
>may be but not good stereo.)

The ability to focus at the image plan while looking at an object appearing to
lie at some other distance, is a learned skill. Since "the eye automatically
focus(es) where it looks", one must overcome this natural tendency in order to
see a stereo image at any plane other than where the print, slide, or screen
actually resides.

For some this can be quite a challenge. Akin, I would think, to trying to 
learn how
to freeview. For some, parallel viewing is a snap, for some cross-eyed 
comes easily.
I can view cross-eyed for days, but still can't view parallel though I've 
been trying to
for 40 years!

As many of you know, I use a 3D system which uses depth of field to extract 
depth
information. I've had the opportunity to see people, initially familiar 
with my system, view dual-lens 3D for the first time. For them, trying to 
learn how to comprehend the stereo information imbedded in two such 
disparate and conflicting dual-lens images was
surprisingly difficult, tiring, and disappointing.

In my particular system I use the aperture stop to select the plane of 
interest, and the
image I get can be a lot easier to view than one which has been shot as a 
diorama.
A selective plane of focus can make viewing 3D easier for some, with a more 
"natural"
feeling to it. For it must be remembered: any image which appears in front 
of, or behind
the actual image plane, must be viewed while focusing only on that image plane.





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