Did you know your digital camera relies on the photoelectric effect in order to take those photographs for your Facebook page?

Photons enter the camera through the lens and are focused onto a special sensor called a charge-coupled device, or CCD. A typical CCD is a light-sensitive material crisscrossed by a grid of tiny channels that divide it into several million separate picture elements, or pixels.

CCD from a digital camera
Source: CCD sensor, Ahmed2IQ, Wikimedia Commons

Each pixel is divided into sections that are covered with red, green and blue filters allowing only certain colors photons through. When the light-sensitive material is struck by incident photons, the photoelectric effect causes it to emit a number of electrons proportional to the number of photons, and the CCD stores those electrons in an electronic device called a capacitor.

After the exposure is over, the CCD circuitry records the amount of charge in each capacitor. The more charge in a given capacitor, the brighter that pixel will shine in the final image. The resulting mosaic is transferred to a processor that converts it into the image you see.