tilted image

[P3D John Bell <johnb@xxxxxx>]

Andy Burr asked: <<Why is being off level a problem?>>

Dr. T responded:
<<Instead of taking a picture of a tree off-level, try taking a picture 
that has sea level in it.  Then tell me what you think.  Doesn't that
make you feel dizzy and disoriented?  Being off level causes no technical
problems with mounting as some people think.  It's just that it does not
work well visually if there are clear indications in the picture that the
image is tilted.>>

I, too, have been curious about why a "Dutch angle" might be 
off-limits in 3-D. The best I could come up with, which seems to be 
what the good doctor is describing, is that the TILT signs within the 
image will conflict with one's internal bodily clues (inner ear?) 
of being on the level. My follow-up questions for the group are:

What if the viewer tilts his or her head to one side to match the 
image's horizon? Does that produce a greater sense of verisimilitude? 
(By "viewer" I don't mean the red-button kind, of course.)

Does the same phenonmenon occur when one tilts the camera forward or 
back instead of side to side? If not, why not?

The 3-D IMAX movie ACROSS THE SEA OF TIME features a roller-coaster
ride (there's an original idea!). Watching that made me slightly 
nauseous, opposite to how going on a whale watch the day after a 
hurricane made me very nauseous. In the boat my eyes said I wasn't
moving and my inner ears said I was. In the theater my eyes said I
was in a moving coaster car and my ears said my chair was bolted to 
the floor. My first tiny experience of *non-motion* sickness.

John Bell
johnb@xxxxxx



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