How Digital Cameras Work

When a digital camera takes a picture, the shutter is opened, and thousands of pixels pick up light, each pixel accumulates an electrical charged based on the light that hits it, the more light, the higher the electrical charge, and the less light, the less electrical charge. After the shutter closes, the charge of each pixel is measured and then converted into a digital number and then converted to a picture by way of an analog digital converted (ADC).

The amount of detail a camera can capture is called the resolution, this is based on pixels the more pixels it has, the larger you can blow up the picture, before it turns grainy and starts to look out of focus. Some common resolutions are 256x256- this resolution may be found on very cheap cameras and is most always grainy and unsatisfactory. 640x480 is on the lower end of regular cameras, this is 307,000 total pixels. 1216x912 pixels- this is a high quality resolution, good for printing pictures, this is 1.11 mega pixels. A high resolution is 1600x1200 pixels, this is a very high resolution and images with this resolution can be printed in very large sizes with a good result this 1.92 mega pixels. Some cameras today have up to 10.2 mega pixels

Digital photography is directly related to the technology used in video recorders, both convert picture into electronic impulses. The first digital images were taken by NASA to map the surface of the moon. Probes would take pictures of the moon then convert the images to electronic signals, then send them back to earth where they would be converted back into a picture. The next major use of digital photography was for spy satellites. The first private industry sector production of digital cameras was in the 1970's when Texas Instruments produced the first film less camera which would use pictures taken onto a minidisk, which then had to be put into a video disk reader, but some say this is not actually a digital camera, but more of a video camera that takes freeze-frames. The first digital camera that could connect to a home PC was the Apple QuickTake 100 camera, which was released in February of 1994.