How to Understand exposure when filming

This is The Substream's "The Film Lab" series on cinematography basics. This is an intro into the basics of exposure. What is the difference between exposure and shutter anyway?

Mike pompously expounds on the basics of lenses and exposure.

Light, a dude, a lens, a camera and film. This is how something magically becomes an image.

Aperture is a fancy word for hole. The aperture of the lens adjusts how big the hole is that is letting light through. F/1.4 is wide while F/24 is more closed down. F/8 is average right in the middle sized hole or aperture.

In photography, exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance over a specified area. The longer the exposure (slower the shutter speed) the more light that can be let in.