Digital Camera Technology

The key difference between a digital camera and a film-based camera is that the digital camera has no film. Instead, digital camera technology has a sensor that converts light into electrical charges.

The image sensor employed by most digital cameras is a charge coupled device or a ‘CCD’. Some low-end cameras use complementary metal oxide semiconductor ‘CMOS’ technology. While CMOS sensors will almost certainly improve and become more popular in the future, they probably won't replace CCD sensors in higher-end digital cameras. CCDs are far more effective in capturing the colors in a scene than a CMOS based camera, as it is able to change each primary color into its own digital profile instead of lumping all the color data together (as in a CMOS camera).

The CCD is a collection of tiny light-sensitive diodes, which convert photons (light) into electrons (electrical charge). These diodes are called photosites. In a nutshell, each photosite is sensitive to light - the brighter the light that hits a single photosite, the greater the electrical charge that will accumulate at that site.