P3D The need for depth in stereographs

[Project3D@xxxxxxx]

Gregory J Wageman wrote to Photo-3D:

<<Stereographs have depth, i.e. produce stereopsis.  Regardless of how they

were taken, an image pair that manifests no depth is by definition not a

stereograph.  The passing off of something as something that it isn't is

in my definition a falsehood.  Particularly by someone who should know

better.  But put that tree branch in there, and hey presto! you've at least

got a stereograph again, which the monoscopic quackery can't do.>>

I'm sorry, but just because you can't resolve the amount of depth in the
distant scene into full rounded 3-D because the angles are too small doesn't
stop the image from being a stereograph. It would be perfectly possible to
enlarge the images with computer enhancement to overcome the limitations of
the film grain, lens resolution etc, to the extent that the depth clues would
become detectable. The fact that the two images were not taken from EXACTLY
the same viwpoint means the we automatically get a stereograph. Whether you
like it or not. 

And because the image doesn't display much in the way of depth doesn't make it
"trickery" to show it. 

I personally think that the audience would find it very strange if I stopped a
stereo show every time a distant subject came up, made them take off their
polarising spectacles, installed a white screen, switched to a mone projector
for the "flat" slide, then returned to the stereo setup for the next bit of
the show - until another "flat" image arrived.

Let's be practical, and get on with making the images and shows that please
us. It really doesn't matter if the occasional slide shows little depth. In
fact, this can be a great device to increase the impact of the next slide
which happens to be a close-up (or whatever)!

Greg finishes his message with:

<<So, what are the alternatives?  I see the following:



1. Take a hyperstereo.  It will at least utilize the third dimension.  If

   hypers aren't your cup of tea then



2. Compose the shot differently; don't make the distant mountains the

   *subject* of the stereograph, but merely include them behind something

   interesting and close-by; or,



3. Find a different subject!  Not every subject is suitable for producing

   good stereo.  Learn to live with this and move on;



4. Take it anyway.  No one's stopping you.>>

And "1", :"2" and "3" all suggest that Greg is always thinking in terms of
images in isolation, which is why I was pleased to see "4" even if it does
seem to imply that Greg doesn't approve of this approach!

Bob Aldridge


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