The filmless camera: How digital cameras store images

by Lisa Cardy

�

PEOPLE have been using cameras and film for over 100 years. When you click the button to take a picture, either digitally or with conventional film, the camera lets light pass through a lens.

�

In traditional cameras, the light contacts light-sensitive film and a negative of the image is captured and revealed upon developing. The key difference between a digital camera and a film-based camera is that the digital camera has no film, so how does it capture the pictures you take

�

Basically, by using sensors to convert light into electrical charges. The image sensor used by most digital cameras is called a charge-coupled device (CCD). The CCD is a collection of tiny light-sensitive diodes, called photosites. Photosites are sensitive to light, the brighter the light, the greater the electrical charge.

�

However, photosites are colour blind and only detect the intensity of light. To capture the colour of an image sensors use filters.�These break light down into the primary colours. Once all three colours have been recorded, they can be added together to create the full spectrum of colours.

�

The electrical charges that build up in the CCD have to be converted into digital signals. This is done by first passing the signal through an analog-to-digital converter (ADC).

�

The ADC measures the depth of the intensity of light hitting each photosite and converts that information to the binary form handled by computers.

�

The image can then be stored on your computer, printed out, manipulated in a graphics programme and emailed to your friends.

�

Is there any other piece of new technology that baffles you If so, why not ask The AnswerBank how it works, just click here