What is Image Sensors of Digital SLR Camera

The type of image sensor in your camera has great impact on the quality of the images you get. The two primary sensor types are CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). CCD and CMOS differ in the ways they record and process light, but the basic layout and capture methods are similar.

CCD is the most common sensor in digicams and lower-pixel count dSLRs. It is also the less expensive of the two sensors. CMOS is used by many of the high-pixel count dSLRs from Canon, Nikon, and Kodak. The advantages and disadvantages to CCD and CMOS sensors are as follows:

Image quality: In the beginning, the cameras that used CCD sensors had better noise-handling characteristics, which reduced the grain-like image degradation resulting from low light and high ISO speed ratings, than those using CMOS. However, the newest CMOS sensors have excellent built-in noise reduction that surpasses most CCD sensors. In fact, current CMOS-equipped cameras from Canon have some of the best noise-reducing characteristics of any camera available.

Resolution:When compared to CCD, CMOS excels because each photosite can be read directly to the sensor, and camera makers can support multiple resolutions from the same sensor. For example, the Kodak DCS Pro SLR series cameras can record 14-megapixel, 6-megapixel, or 3-megapixel images. With a CCD-equipped camera, all 14 megapixels of information would need to be read and converted. The camera would then need to discard the excess data. This wastes processing time and battery power. CMOS, on the other hand, simply reads the required number of photosites and converts only those necessary to record the image.

Power consumption: CMOS technology has the advantage of lower power consumption than CCD because most of the processing is done on the sensor itself instead of in a separate transfer cell.

Cost: The biggest drawback to CCD sensor technology is the cost. CMOS is less expensive to produce.