From: Jonathan Walley (email suppressed)
Date: Tue Oct 30 2007 - 09:16:33 PDT
My understanding is that we spend half our time in darkness and half
"in light" while watching a film. As for what we do with the rest of
our time, the ratio varies :-).
I thought that it didn't matter what sort of projector was being used -
a two-blade shutter flashes each image twice with corresponding
durations of darkness, while a three-blade shutter flashes each image 3
times with corresponding durations of darkness. Either way, the
light/dark ratio is still 1:1. What matters is "bumping up" the number
of flashes to at least 48/second (72/second with three-blade
projectors), as this crosses a perceptual threshold beyond which we
don't see flickering light but a consistent light source. I don't think
the gauge of the film/projector matters.
This is what I've read, anyway, and it's what I teach. I'd love to hear
other people on this matter, esp. if any of the above is wrong or
Granville, Ohio 43023
On Oct 30, 2007, at 9:53 AM, Yoel Meranda wrote:
> A question I'm curious about...
> When a film projector is running, what is the percentage of time the
> light is interrupted by the shutter? In other words, what percentage
> of what we see is darkness?
> I realize that this question will have different answers for each
> I am mostly curious about 35mm projectors but any clue on any other
> projector would be great. Even guesses would be fine if no one has
> concrete answers.
> For info on FrameWorks, contact Pip Chodorov at <email suppressed>.
For info on FrameWorks, contact Pip Chodorov at <email suppressed>.