What is the difference between CCD and CMOS and which is best?

 

Good question, this sometimes confuses people as the resolutions are very often similar, but this doesn't necessarily mean that they are the same quality image.  See below for a more techical reasoning:-

 

CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) image sensors are two different technologies for capturing images digitally

 

Both types of imagers convert light into electric charge and process it into electronic signals. In a CCD sensor, every pixel's charge is transferred through a very limited number of output nodes (often just one) to be converted to voltage, buffered, and sent off-chip as an analog signal. All of the pixel can be devoted to light capture, and the output's uniformity (a key factor in image quality) is high. In a CMOS sensor, each pixel has its own charge-to-voltage conversion, and the sensor often also includes amplifiers, noise-correction, and digitization circuits, so that the chip outputs digital bits. These other functions increase the design complexity and reduce the area available for light capture. With each pixel doing its own conversion, uniformity is lower

 

So we can see that CCD has higher uniformity which gives a better quality, CMOS has a lower uniformity (lower quality).  If you ever get a chance to run them side by side as I've done, you can see the difference, especially at night.