P3D Re: Fine for window violation$

[aifxtony@xxxxxxxxxxxxx (Tony Alderson)]

>Jon Golden wrote (digest 3006):
>Gee...Disney and IMAX are making million$ with their programs filled with
>window violations....should we fine them?<

Maybe in the future People's Republic of Stereoscopy.... (-:

But seriously, 3D projection on a BIG screen is real different from what we
P3Ders usually do.  Consider that with these formats, your peripheral
vision is pretty well filled.  The "window violations" are at the edges of
the screen, the main action is nearer the center, thus it is a lot easier
to ignore (and compensate for) the conflict of depth cues.  Consider also
that IMAX completely avoids the issue by converging infinity at the screen.
They can get away with it because of the size of the theater.

Furthermore, it is a lot harder to shoot stereo for these formats without
breaking the rules.  Visualize for a moment how far you are from the screen
in a movie theater.  Maybe 20 feet at the closest?  How much parallax is
there from 20 feet to infinity, if you are not going to allow divergent
viewing? (I ask rhetorically...)  A 70mm movie frame has a picture area
about 50 mm wide (roughly 2 inches).  If we blow that up to a 30 foot
screen, then our magnification is 180x.  If you wanted to keep strictly to
the "rules" we promogulate here (which I endorse, of course!), you would be
restricted to an on-film deviation of .36 mm! And you guys thought 1.2 mm
was restrictive.

Well, practically speaking, it can't be done.  Which is why divergence and
window violations are so common in motion pictures. Aside from the obvious
fact that audiences like it, there isn't anywhere else to put the 3D but in
theater space. We make a virtue out of necessity here.

Tony Alderson
aifxtony@xxxxxxxxxxxxx



------------------------------