How Does a Digital Camera Work?

Digital cameras focus light onto a semiconductor to create a digital image. They have built-in computers that record images electronically. It is one of the most remarkable techonological breakthroughs in electronics because it is so different from the 35mm cameras that depended on chemicals and mechanical processes.

• Digital camera images are represented in bits and bytes, the language that computers recognize. A digital image is a string of 1s and 0s that represents pixels that make up the image. Just like the 35mm camera, the digital camera has a series of lens that focus light to create an image of a scene. It focuses the light onto a semiconductor device that records the light electronically, instead of on film like the 35mm camera. The digital camera's computer then breaks this electronic information down into digital data.


• The image sensor or chip contains a charge coupled device (CCD) that converts the image light into electrons. Once the sensor changes the light into electrons, it reads the value of each cell in the image. This is where the CCD transports the charge across the chip and reads it at one corner of the arrangement. An analog-to-digital (ADC) turns each pixel's value to a digital value by measuring the amount of charge at each site and converting that measurement to binary form.


• Pixel is short for picture elements and is measured in megapixels, which is equal to one million pixels. The amount of detail that the camera can capture is called the resolution and is measured in pixels. The more pixels a camera has the more detail it can capture and the larger a picture can be without becoming blurry.