Re: Polarized viewing of IMAX 3D

[P3D Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 6:55 PM -0800 2/27/97, P3D wrote:
>It is surprising that "L5..." is presented in La$ Vega$ using LCD shutter
>glasses and the recently reported discomforts.  In Vancouver, Canada, it is
>presented as viewable with standard polarized glasses.

I'd like to see it that way for comparison.  I'm not all that impressed by
the LCD system.  It's too heavy.  There's no ghosting, but there is
sometimes clearly visible flicker (I didn't see any in the underwater film,
but it was there in L5.  I don't know if this was just because the images
were generally brighter in L5 or if the headset was a little out of phase
with the screen.  On second thought, the first hypothesis sounds more
plausible...).

My biggest problem with the IMAX movies is that they can't seem to get the
convergence right.  I'd originally thought that they were separated beyond
infinity, but at L5 I did some surreptitious testing & the effect was
clearly in the opposite direction, i.e. they were having me converge
somewhere near the tip of my nose.  Possibly they do this on purpose to
make the images look smaller & closer to life-size.  It may not be a
problem for people past 40 or so (whose eyes tend not to change focus at
different convergence angles) but it gives me severe eyestrain.

-Jim C.

----------------------
Jim Crowell
Division of Biology
216-76
Caltech
Pasadena, CA
(818) 395-8337
jim@xxxxxxxxxxxxxxx



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