I assume you are talking about older 8MM films. They were shot at 18 frames per second, which is slower than the current video standard of 30fps . read more
Some actually filmed at rates faster than 24 frames per second, meaning that the characters moved in slow motion. What it all boils down to is: Slow camera speed equals fast playback. Fast camera speed equals slow playback. So relax - Charlie Chaplin did walk at normal speed. There were no bugs-a-biting in his pants causing him to move that fast. read more