There are only two types of image sensors used in digital cameras, CCD chips and CMOS chips. CCD or Charge Coupled Devices contain a series of capacitors that gather a charge that is proportional to the amount of light that is hitting it. The amount of charge on each capacitor is then converted to a numerical value by the camera’s internal program to produce an image. CMOS or Complementary Metal-Oxide Semiconductor is a name given to a group of integrated circuits that share a certain design. The CMOS image sensor is just one type of CMOS IC that has been created specifically for capturing images.
A CMOS image sensor captures light intensity through a series of photodetectors which are then coupled with an amplifier to reach a level high enough to charge for quantification. As in CCDs, the data in each photodetector would correspond to a pixel in the image output. The advantage of CMOS sensors over CCDs is the low cost of producing them. This low cost of production would easily translate to cheaper cameras. CMOS sensors also consume considerably less power compared to CCD sensors, giving CMOS cameras a longer life of use before the battery runs out. This is why most of the cameras built into mobile phones and laptops have CMOS sensors.
But not all the advantages belong to CMOS sensors, CCD sensors are more sensitive compared to the previous ones, which results in better images, especially in low light conditions. CMOS sensors are also more susceptible to noise; this means that the images captured by the CCD sensors are cleaner or less grainy. For these reasons, most cameras and almost all DSLR cameras employ CCD sensors. There is simply no reason to sacrifice quality, especially when doing professional photography. The CCD sensor is also a contributing factor to the high price of DSLR cameras, as CCD sensors with very high resolutions are considerably more expensive.
Each of these sensors has its own advantages and disadvantages that make them a perfect fit for a specific niche. CCDs are excellent at capturing high-quality images, making them perfect for both professional and amateur photographers. CMOS cameras are cheaper and consume less power, making them a good choice for multi-use portable devices like mobile phones, PDAs, laptops, and gaming devices where image quality isn’t really a priority. The gap between the two types of sensors has been narrowing as the technology has developed. It would only be a matter of time before it becomes difficult to point out the advantages and disadvantages of each.