Ccd Camera

Ccd Camera

In many digital still cameras, the image sensor capturing our photograph in place of the standard film is a CCD (charge-coupled device). How it is manufactured and what happens in it when we press the shutter release button is of interest to any good photographer, because it may contribute in taking better photos. Moreover, basics of lingo are useful for the understanding of characteristics of a camera, especially if you are going to buy one.

A pixel element of a CCD, in its simplest form, is basically a MOS capacitor, i.e. a semiconductor structure made of three layers: Metal-Oxide-Semiconductor. The semiconductor part of the MOS is simply silicon while the oxide is silicon dioxide, acting as an insulating layer. The metal is not a real metal substance, but rather a heavily doped polysilicon layer and is named "gate". Basically, the image is formed within the semiconductor part of the MOS system and the metal gate is used for shifting such image.

The digital cameras megapixels madness is very similar to the personal computer Mhz madness back in the 90s. The number of pixels a camera uses to produce a digital photo is just one element in determining the photo quality. Another important element that is usually forgotten is the sensor size. Here is why.

Digital cameras use an electronic sensor (also known as a CCD) in order to capture a digital photo. This sensor replaces the old film rolls used by traditional cameras. The electronic sensor is built from small light sensors also known as pixels. When you take a photo the camera opens the shutter for a certain amount of time. During that time light hits each individual pixel. The amount of light that hits each pixel determines its intensity (also known as the pixel value). A digital photo is comprised of many pixels each with its own pixel value.

Ccd Camera