In a digital camera, the lens forms an image of the scene on a small electronic chip called the image sensor . The sensor measures this light and converts it to a digital image. Figure 1 shows an image sensor like the one used in Bigshot.
The sensor works much like the retina inside the human eye . On the retina, a dense grid of light-sensitive cells converts incoming light to electric signals. These signals are carried to the brain, where they are interpreted as images. Similarly, Bigshot's image sensor has a grid of detectors called picture elements, or pixels for short. Place the mouse over Figure 1 to see how an image sensor's pixels look under a microscope. When exposed to light, each pixel generates an electric charge that is proportional to the brightness of the light it receives. The charge is converted to a number and stored in memory. The numbers collected from all the pixels form a complete digital image.
Let's take a closer look at how an image sensor works.