Digital Cameras : A SearchMeSilly Guide

A digital camera, like its analogue counterpart, has a lens, an aperture and a shutter.

• A lens – focuses light inside the camera so it can expose an image.
• An aperture – an adjustable hole controlling the amount of light which passes through the lens.
• A shutter – a mechanical device that opens and closes the lens aperture, controlling the length of time the light enters.

One of the main differences between a digital and a 35mm film camera is how the image is captured. Instead of film, a digital camera uses a solid-state device called an image sensor. Most image sensors are a charged-coupled device (CCD) which converts light into an electrical charge. The charge is stored in analogue format and then digitized. A CCD contains potentially millions of photosensitive diodes called photosites, photoelements or pixels. Each photosite captures a single pixel in the photograph.

• consume less power
• smaller, lighter
• more energy efficient
• can have other circuits included on the same chip, such as camera controls and image compression