What are the dots that appear in the upper-right corner of a movie screen?
Each reel of film actually has two sets of cue marks. Before one reel ends, the projectionist loads the next reel in a second projector, with about nine feet of leader, or blank film, between the lens and the start of the reel. The first sequence of dots, which starts about nine seconds before the end of the reel, cues the projectionist to start the second projector running.
At the second set of dots, which marks the end of the reel, the projectionist throws a switch that changes the sound and picture source from the first projector to the second. At this point, which is usually a dark scene change, the two projectors are cued up at the same point in the film. It's a process that's worked for 100 years,
but the advent of digital projection technology means it's not likely to make it another 100.
Receive post updates by Email