Does film actually stop at each frame when projected?

Question

in a movie projector (with actual film, and not a digital tape or whatnot) does the frame actually stop over the lense? or is there continuous motion with a shutter for the light?

if you know the answer, can you back it up in a meaningfull way?

Help settle a bet!!! thanks.

JMK

Answer 1

"The primary purpose of the spool assembly is to move the film through the projector. While the motion appears continuous, there is actually a slight pause after each frame. This allows light to be passed through the image and projected on the screen. "

Answer 2

Good ol wikipedia provides you with your answer :p
http://en.wikipedia.org/wiki/Movie_projector

Specifically: (from wikipedia)

A commonly-held misconception is that film projection is simply a series of individual frames dragged very quickly past the projector's intense light source; this is not the case. If a roll of film were merely passed between the light source and the lens of the projector, all that would be visible on screen would be a continuous blurred series of images sliding from one edge to the other. It is the shutter that gives the illusion of one full frame being replaced exactly on top of another full frame. A rotating petal or gated cylindrical shutter interrupts the emitted light during the time the film is advanced to the next frame. The viewer does not see the transition, thus tricking the brain into believing a moving image is on screen. Modern shutters are designed with a flicker-rate of two or even sometimes three times the frame rate of the film, so as to reduce the perception of screen flickering. (See Frame rate and Flicker fusion threshold.)

(Found using google - you should try it some time!)

Answer 3

The film MUST stop at each frame to allow the still image to be projected on the screen. Think of it this way, when a film is created, light is exposed onto still film, frame by frame. Therefore, to recreate a true image, it must be displayed still frame by still frame. Any movement of the frame during either exposure or display will result in blurred images.

Finally, my other reasoning for this is that in the "old" days, when the frame by frame mechanism used to jam, the intense heat of the projector bulb (globe) would burn through a single frame of the film...so the film would stop, and then the image would melt before your eyes......disaster!!!!

Answer 4

The tape actually continuously moves through the projector and a motion shutter shuts for the lights. The film is being constantly strung through the projector so there's no way for it to stop and then show another picture.

Hope that settles your bet!

Answer 5

It has to stop, because if it didn't the picture would be blurred. The film is advanced by a little hook gadget which advances the film by exactly one frame; while this is happening, the light is cut off by a shutter. Once the film has stopped moving, the shutter opens so you can see the image.

Answer 6

Yes. It moves, stops, exposes a frame, then moves on to the next frame. Look at some back lit film if you ever get a chance (not projected - the film itself). It's a series of still frames that change very little from one to another. It's the same playing it back. That familiar clack-clack-clack-clack sound a projector makes is from the film starting and stopping so fast.

When I was a kid, high school teachers use to bring these reel to reel films into class when they got to lazy to teach. So, you've sort of dated yourself.