Here, for those of you who have 23 minutes to spare, is maybe my favorite Buster Keaton short, The Playhouse. It was made in 1921 and it's still brilliantly clever and entertaining. Which is more than I can say for a lot of comedy made since last Thursday.
It was also, at its time, a breakthrough in the area of special effects. Early in the days of cinema, filmmakers learned a primitive but workable way to do split screens and allow, for example, someone to play their twin in the same shot. They'd tape off one half of the camera lens and film, say, the left side of the scene. Then they'd roll the film back and expose the same piece of film again, this time with the other half of the lens taped off. The images usually did not match up perfectly. There was usually a fuzzy line in the center of the image and, of course, the actors in the scene had to guess how to coordinate their actions but it worked. Sort of.
For The Playhouse and a few other early films, Keaton and his tech crew devised a way to do it better. They built a shutter mechanism to fit over the camera lens — a series of interlocking windows that could be open or closed to matte off part of the lens. It gave them a more precise fit than tape on the lens. They also worked out elaborate charts and stopwatch handling that would enable Keaton to do his motions precisely on certain beats so they'd coincide with actions in other takes.
This is all something to keep in mind when you watch the trick shots in this film. They could not edit two takes together or do parts of a shot out of sequence. They'd film the left side of the scene, then Keaton (if necessary) would change outfits and they'd film the right side. And if the two performances didn't match up right, they'd have to throw the whole thing out and start over. It must have taken days to do some of these scenes. The rest of it's pretty darn clever, too.
