Projectors {movie projector}| can use holes in film sides {sprocket, movie film} to position new film frames behind lens, 16 or more times a second. Movie projectors hold film frames for 1/30 second. A rotating disc blocks light while film frames change. Film moves by gears pulling film through by film sprockets. Take-up reel turns as main reel turns.
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7-Machine-Kinds-Optical-Projector
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Date Modified: 2022.0224