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Technology

How does a camera work?

A camera works by focusing light through a lens onto a sensor (or film). The lens projects the scene; the sensor measures the light's brightness and color at millions of points (pixels) and records them as a digital image.

See it in motion.
Watch a 2-minute animated lesson that shows exactly how a camera works.
▶ Watch the visual lesson

Step by step

  • 1A lens bends incoming light to form a focused image.
  • 2The aperture and shutter control how much light enters and for how long.
  • 3A digital sensor turns light into electrical signals at each pixel.
  • 4Those signals are processed and saved as an image file.

Frequently asked questions

How does a digital camera capture an image?
A lens focuses light onto a sensor that measures brightness and color per pixel, then saves it as a digital file.
What do aperture and shutter speed do?
Aperture sets how wide the lens opens (light + depth of field); shutter speed sets how long the sensor is exposed.
How is a camera like the eye?
Both focus light through a lens onto a light-sensitive surface — a sensor in a camera, the retina in an eye.

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