ABSTRACT

Currently there are two types of sensor available that, between them, dominate the High Definition (HD) arena: charge-coupled devices (CCDs) and complementary metal-oxide semiconductor (CMOS). Both have advantages and disadvantages. The purpose of any sensor is to convert small parts of the image formed by the lens, and therefore being made up of varying amounts of light energy according to the brightness of the original scene in that particular area, into amounts of electricity corresponding to the light energy. Each of these discrete portions of the image is usually referred to as a pixel. It is important that the number of electrons coming out of each pixel can be assessed and recorded. CCD and CMOS sensors do this in slightly different ways; the way they do it and, more importantly, the way they divide up the primary colors Red, Green and Blue is crucial. Let us take a look at each type.