16. Explanations

CMOS Vs CCD, Sensor Formats

As can be seen by reading the APN technical data, the sensors are different in size and design, although the principle appears to remain the same. There is a matrix of photosensitive cells whose job it is to capture light and transfer it in the form of electrical current to a converter. It then has to recompose all these pixels into a "picture-element". The difference between CCD and CMOS is difficult to grasp in a practical sense, because they are so very similar. It can be said, for instance, that CMOS consists of a matrix of photosensitive cells, which preserve their load and transfer it themselves to the converter, whereas CCDs consist of a matrix of photosensitive cells that transfer the load to a collector, which then transfers all of the loads to a converter. So are you clear about that?

In practice, CCDs are more expensive, harder to manufacture, and more energy-hungry, but of higher quality. CMOS sensors are generally used only in entry-level models, of the web cam and "small" APN type. "Unfortunately" a certain manufacturer called Canon has upset the apple cart by fitting its high-end reflex cameras (of the EOS 1Ds and currently the 300D type) with CMOS sensors. Shock! Horror! Will the CMOS perform better than the CCD? Has the rest of the world been mistaken? The true situation is much more banal: The CMOS is less sensitive to "blooming", less expensive but barely less effective than the CCD and it can be enhanced by digital processing of its data. Thus an excellent CCD with a lousy converter behind it will produce bad images, while an excellent CMOS linked to an excellent converter will produce excellent results - QED. This is one of the things that enables Canon to offer such a value-for-money product.