Re: Chicken Little Digital 3D Report


Martin Hart wrote:

Would somebody else step in here and try to get it across to this guy that you never, never, never want to shoot 3-D with left and right exposures made sequentially? I'm not doing any good at trying to throw logic into the discussion.

This guy appreciates your efforts to throw logic, as well as to bring in a closer... but, to anyone who might turn up, please read at least the whole message of mine that preceded this one...




In article <Curef.12449$GT3.5378@xxxxxxxx>, pwallace@xxxxxxxxxxxx says...


Martin Hart wrote:


In article <QWlef.12400$GT3.11442@xxxxxxxx>, pwallace@xxxxxxxxxxxx says...


Martin Hart wrote:



In article <lU4df.16794$7s1.6317@xxxxxxxx>, pwallace@xxxxxxxxxxxx says...

<SNIP>

Do you (anyone) know how Imax-3D handles this? Are their frames shot simultaneously or "staggered"? And, if the latter, do they stagger their projectors in polaroid venues? Seems a tangled web they weave...


You never want to shoot two images sequentially. It was bad when it was done in Kinemacolor back in the early 1900s and it would be bad for 3-D. Projecting sequentially isn't nearly as bad however when the sequence bounces back and forth between the two views very rapidly as is claimed for "Chicken Little". It is virtually impossible for the eye to detect that it isn't seeing both images simultaneously.

Afaics... *if* a new filmed moment is shown at each projector-flash, then the filmed moment should match the time at which it's flashed. (That's a lumbering way of describing ordinary movies.) But then, it *seems* that the same should be true even if, through the magic of shutter-glasses (or very fast eyelids), each eye sees only alternate images... as with DLP-3D. (Consider, e.g., what you'd see if you wore shutter-glasses while watching "real life".) So... if you know that the movie you're shooting is destined only for alternate-frame viewing, then you ought to likewise alternate the frames' exposure cycle. If you don't, then laterally moving objects will show a bogus depth-shift (because of the slight parallax inconsistency), even if the spectator doesn't subjectively notice that anything's amiss. And I saw such depth-shifts in CL-3D. (If the foregoing is incomprehensible, please say. I'm more than willing to try again... inasmuch as I, at least, find this issue fascinating.)


You are losing sight of the purpose of the system used for "Chicken Little". They are not showing alternate frames because they want to, they're showing them because they have to. BUT during the 1/24 second that they're on screen the projector alternates back and forth between the two views many times, with each eye seeing only its own view. It's no different than the shutter interruption of a single frame in a 

--

/---------------------------\
|    YOUR taste at work...  |
|                           |
|  http://www.moviepig.com  |
\---------------------------/

.

Quantcast