How a Film Projector Works, And Why They're Still Mechanical Marvels

When going to see a movie, many of us probably go out of our way to make sure the theater has been upgraded with high-res digital projectors. The golden age of film might be behind us, but as engineer guy Bill Hammack explains, the projector is still an impressive feat of mechanical design, capable of creating one of the best optical illusions of all time.

It’s taken for granted that flashing a series of still images in front of our eyes will fool the brain into seeing motion, but creating that illusion is actually far more complicated as Hammack explains in this video.


It might look like film is simply being dragged through a projector, but the engineering that ensures that each frame of the projected image isn’t just a blur on screen will give you a newfound appreciation for a technology that’s been in use for well over 100 years.



As a movie lover, I’ve always wondered how they worked, but this is an absolutely astounding piece of engineering. So very complex, yet so simple in design. Never knew about the flicker —> flick fact, and though I did know that sounds were kept on the film, hadn’t thought about them being offset to get the sound right.

That does leave me with another question though, since light travels faster than sound, do they factor that in as well to make sure the sound is perfectly timed? Seems like it would be different for different sized cinemas as the length of time to project to the screen and be seen would differ based on how far the screen is from the projector. So many questions!