Re: 16mm film projection speeds

From: Myron Ort (email suppressed)
Date: Thu Jul 31 2008 - 23:54:01 PDT

thanks amanda for some very interesting considerations and

yes ok, guess I have decided 24fps will be the structural basis for
my rhythmic pulse arrangements, this film will be single frame images
followed by black frames, so I will indeed be exploring what was said
before about the eye/cognitive/perceptual system doing some fill in
work. there will also be some clusters of (alternating) frames with
resultant animate qualities, in which case, I will be translating the
timing of the usual 2 frames per "drawing" into one "scratch" frame
followed by the one black frame as the equivalent. I think I have
done something like this before and it works to my satisfaction, an
interesting effect. I may, in time, make something along these lines
in both 16mm and 35mm. It would be nice to have something which can
be projected as film, although it does look like I need to
investigate transferring things to digital which does bring up the
question of how digital will translate a single frame image running
at 24 fps. I am not too worried about flicker because this film idea
already embraces flicker in its premise.

(to repeat)

Question: what does happen in a digital transfer when there is one
frame of image surrounded by black on both sides, at the 24fps speed?
will the digital have the same kind of impact as the film? or even


On Jul 31, 2008, at 11:03 PM, amanda christie wrote:

> something to consider when choosing a projection speed is flicker.
> you're right in saying that at 18fps the image will be on the
> screen longer... but the flicker will also be more visible...
> because the screen will be black longer.
> 24fps was accepted as a standard frame rate when sound was
> introduced because that was how sound sounded best at that time....
> but later on, as technology advanced, it was realized that for the
> eyes and the brain... something like 60fps was best (someone can
> correct me with the exact number if they know it... it's 2:30 am
> here, and i have no reference books handy)..... so basically... at
> anything slower than 60 fps, the human mind tends to drift and
> wander in between frames, and therefore we are more easily
> distracted... ( our minds are speedy little things)
> so to compensate for this, projectors have multiple blades... so
> for instance, in a two blade projector, each image is projected
> twice, as the two blades rotate one cycle per frame... this creates
> a flicker of 48fps... better than 24fps, but still less than 60fps,
> so the mind still wanders....but not as much....
> enter cinemascope.... apparently, the human eye can take in 1:85 in
> peripheral vision... but the human mind wanders between the frames
> at the 48fps of a double blade projector (which projects 24
> images, 2 times per second)... so they came up with the super wide
> screen of greater than 2:1 ratio (there were various ratios used as
> the formats progressed) because it covers more than peripheral
> vision can cover... therefore... when your mind wanders between
> frames, it wanders and explores the rest of the projected image
> that it cannot take in during the peripheral glance.
> at least that's what i've been told... or that's what i've
> understood when i've been told.
> someone please correct me if i'm wrong.
> if i were you... i would create for 24fps... and if you're up for
> it... make or modify your own projector to suit your desired needs
> and effects, by playing with belt placement and shutter design.
> with a pounding headache,
> amanda dawn christie
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For info on FrameWorks, contact Pip Chodorov at <email suppressed>.