P3D IMAX OUT

[John Toeppen <toeppen@xxxxxxxxxxx>]

  IMax max out after an hour.  Michael Georgoff said:

And I think what was going on was some sort of convergence
fatigue, wherein my powers of accommodation were slammed around much
faster than was good for my brain.  Way too much jumping from image to
image without enough convergence adaptation time?  I've never
experienced this in polarized slide shows...

The Luxor in Las Vegas has an IMax.  I noticed that only infinity
objects
overlapped on the screen.  Since the underwater footage was all closeup,

and the separation large for such close work, nothing was in the screen
plane.
While this is all very in your face 3D and all, it did hurt.  It was
worth
it, though the extreem out of screen effect was way overdone and does
result in fatigue.  One thing for sure: you would have to be totally
blind
in one eye to not see 3D there!

Generally, 3D can suffer from a whole host of mis-cues that undermine
the persuasiveness of the experience.  While these can be control
points, sometimes they are factors which are out of control.  Or
sometimes
people strictly adhere to there own personal opinion.

My personal opinion is that pain is bad.  The object of primary interest

should be overlapped on the screen plane, or not too far behind it.  You
can
occasionally have something stick out in front of the screen if you have
enough
in or behind the screen plane to "anchor" the extended object.

Some people like to suffer, don't mind ghosts, and produce images
where things that are not the subject are easy to see, and the subject
is
hard to see.  Often just to satisfy some rule of thumb which became
a hard and fast rule.

Contrast is necessary (or color contrast) for the brain to see good
3D effects.  Thus, good subjects are contrasty and will ghost
when projected or viewed with shuttered glasses, unless the
subject is overlapped.  Sometimes the branch that you include in the
subject
as a foreground cue may need overlapping to prevent ghosting.  Then
the subject may not be overlapped, but it may not be necessary.

Each image is a judgement call.

I don't specially mount my slides for use with my projector.  I adjust
as required, not often, just sometimes.  I find it good practice to tell

the audience to close one eye until the adjustments are made.  You can
go on for a few hours this way.  The limit is the fatigue of the
projectionist pushing
slides through this 1 kilowatt TDC.

I have seen some of my DepthCharge images using a LC polarizing
projector.  It is not 70mm.  It is not a Realist.  It is good, and it
allows mass publication of images, and mass viewing.

Perhaps this next wave of 3D will really stick.  Many new technologies
will allow for more than personal photography.  The JPS can become
the "View Master" or "Keystone" of the next century.

John Toeppen
http://home.pacbell.net/toeppen/




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End of PHOTO-3D Digest 2829
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