It can be seen from the working principle of the two types of photosensitive devices that the advantages of CCDs are good image quality, but due to the complexity of the manufacturing process, only a few manufacturers can grasp them, which leads to high manufacturing costs, especially for large CCDs, which are very expensive.
At the same resolution, CMOS is cheaper than CCDs, but CMOS devices produce lower image quality than CCDs. So far, the vast majority of consumer-grade and high-end digital cameras on the market use CCDs as sensors; CMOS sensors are used as low-end products in some cameras. If any camera manufacturer uses a CCD sensor , Manufacturers will spare no effort to publicize it as a selling point, even as a "digital camera." For a time, whether or not a CCD sensor has become one of the criteria for judging the quality of digital cameras.
The main advantage of CMOS for CCDs is that they are extremely power-efficient. Unlike CCDs made up of diodes, CMOS circuits have almost no quiescent power consumption, and they only have power consumption when the circuit is switched on. This makes the CMOS power consumption is only about 1/3 of the ordinary CCD, which helps to improve people's mind that the digital camera is the "electric tiger" bad impression. The main problem with CMOS is that when dealing with fast-changing images, overheating occurs due to current changes. If the dark current is suppressed well, there is no problem. If the suppression is not good, noise is very likely to appear.
In addition, the CMOS and CCD image data scanning methods are very different. For example, if the resolution is 3 million pixels, then the CCD sensor can continuously scan 3 million electric charges, the scanning method is very simple, just like the bucket from one person to another, and only after the completion of the last data scan Amplify the signal. Each pixel of a CMOS sensor has an amplifier that converts the charge into an electrical signal. Therefore, CMOS sensors can amplify the signal on a per-pixel basis. This method saves any inefficient transfer operations, so it requires a small amount of energy to perform fast data scans, and noise is also reduced. This is Canon's pixel full charge transfer technology.