Re: Rule-breaking

[P3D Paul Pascu <pascu@xxxxxxxxxxxxxxxx>]

At 05:53 PM 6/24/97 -0500, you wrote:
>We recently had a discussion here about when it is OK to break the
>"entire image in focus" rule.  Several of us agree that it *can* be
>succesfully broken, but not *always*.  We've been unable, as yet, to
>codify exactly *when*.  

Can it be codified or is it really a matter of personal taste and creativity?

>The conventions regarding the stereo window came about because of the
>practical necessity of having a border around an image, particularly
>with 5-perf Realist and narrower formats. 
>
>I've already observed how the VR folks aim to immerse you by involving
>your peripheral vision.  I don't know of any panoramic, stereo cameras,
>or viewers for that matter.  But even with 8-perf, the image is only just
>so tall, so there is a border that must be dealt with.

If you mean that the image doesn't go on forever, of course.

>Given that, people learned from trial-and-error what looked "natural"
>and what didn't.  We've all stood inside a house and looked out a real
>window, to see the scene lying beyond.  The scene doesn't appear to jut
>into the house.  Given that observation, it is natural for a stereo image
>to try to emulate this.  I've also commented on how window violation
>produces conflicting depth cues.  This is another viewer-comfort issue
>as well as a "realism" issue.  

These pionts all relate to "realism" which was part of the reason for my
original post - duplication of reality doesn't have to be the only game in
town.  Some prefer it and that's fine.  But we aren't looking out a real
window.  Of course there's a border to an image but it doesn't necessarily
have to be a window that separates one from their 3D creation if the
duplication of reality is not part of that creation.

>As Dr. T. pointed out, only the sides
>of the window usually have disparity (and hence 'depth'), so you can
>"get away with" violating the bottom of the window easier than the top
>or sides, if it isn't extreme.  If you can find a "creative" way to
>violate the window, by all means go ahead!  But to me, every example
>I've ever seen (or caused!) just looks "wrong" (as in "unnatural",
>"strange" and even "disturbing in a bad way".)

Of course it's unnatural.  

>To reiterate, you have to know *why* there are rules.  Once you know
>this, you can decide intelligently if and when to break them.  You have
>to realize that stereography has over a 100-year history.  Some quite
>clever people have been thinking about these things for a long time.
>It would be somewhat arrogant of me to think that I could out-think
>all of them.  Still, sensibilities change, and where the only reason
>for a rule is convention, this can be changed. :-)

There have been many examples in history of deviations from accepted norms
and some of these norms have existed longer than 100 years.  If we really
thought that a 100 year history perfected a process, what would that do to
progress.  If innovation is arrogance, so be it.

>Dr. T. already pointed out some situations in which some toe-in is
>necessary, or even required. 
>       .       .       .
>Also, in virtually every example there are ways to avoid needing any
>toe-in, most requiring more flexibility in mounting (custom masking,
>etc.). 

The point isn't that you can find a way to do then without the toe-in or
that toe-in should be used if necessary.  The point is the toe-in can be
used - for those examples and possibly taken a step further.  They may
reduce the "realism" that you may seek but that's your taste, not a
universal rule.

>There is truth in this analogy (music); however, no matter what dissonances
>one uses in composition, one can't damage the listener's ears, only
>offend their artistic sensibilities.  Unfortunately due to the nature of
>vision, a badly-mounted stereo *can* cause physical pain in the viewer.

I never suggested that anyone should damage themselves.  For some, cross
viewing is uncomfortable (and unnatural) but this doesn't make it wrong.

Paul Pascu


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