P3D Re: Faking it? No!

["Gregory J. Wageman" <gjw@xxxxxxxxxx>]

Sorry for the completely quoted post with no added content.  We are having
power problems here in the Silly Corn Valley and my telnet session was
dropped while I was composing the response.  Unfortunately, this seems to
cause Unix Mail to repost the original message as my reply.  Here's the
content:

Mike K. wrote:

>IMO, it's only quackery when in real life the photographer would have
>seen depth when looking at the scene with his/her eyes -- but the
>image provided shows none.

>If the actual scene *is* flat, then is mother nature guilty
>of quackery because she shows no depth to the human eye? 

The *scene* is most decidedly NOT flat.  It is only our small interocular
combined with the extreme distance and the limits of our visual system
that make it appear flat.  Choosing to take such a picture (we ARE after
all talking about an act of volition, not a natural phenomenon), where
stereopsis will not occur, and passing it off as a stereo photograph, is
IMO bordering on the same sort of "quackery" as mounting the same image
in a stereo mount, the fact that the former was taken with a stereo camera
notwithstanding.  A difference that makes no difference, is no difference.

If such pictures happen to win awards in supposed "stereo" competitions,
well this is more a comment on the judging of such competitions than it
is a reflection of the value of such photographs as a good use of the
stereo medium.  Non gustibus disputandem est.

>To me, quackery is when a falsehood occurs, and a stereo image
>that is true-to-life isn't a falsehood, even if it looks flat.

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.

>That's a sticky path for arguement.  One also won't experience the
>heat, the wind, the chill, the hotdog smells, etc.  What the realist
>might show is indeed a subset of the experience, but a panaoramic 
>image also is a subset as well.  Saying one subset is proper, and
>another subset isn't ..... uh..... sticky.  :-)

Firstly, Dr. T. was obviously talking about the photograph successfully
capturing only the visual portion of his experience.  I maintain it doesn't
even do that.  No need to digress.

Secondly, I never said that there was any "proper" or even "improper"
subset; I simply contradict his assertion that the attempted Realist
stereo photograph of a landscape virtually at infinity reproduced the
in-person visual experience to any significant degree.  That would be
giving a lot of credit to *any* means of mechanical reproduction.  One
would need an IMAX 3D theatre or a virtual-reality equivalent to even
begin to approach the necessary field of view of the actual experience,
and you would still be lacking in several important visual cues such as
motion parallax, accomodation, etc. that are lacking from most film-based
forms of 3D.

The logic being used here seems to be that because the Realist photograph
suffers one of the same failings as the human vision system does in the same
situation, it has suddenly become "lifelike", despite all of the known
and previously discussed flaws of the system.  Great, it fails the same way
as human stereoscopic vision.  That's precisely why I maintain that such
images are among the poorer uses of the stereoscopic system!

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.

        -Greg W. (gjw@xxxxxxxxxx)


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End of PHOTO-3D Digest 2945
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