When talking about image sensors, we always stumble across two types – CMOS sensors and the CCD sensors. And there are many arguments comparing CMOS sensors vs. CCD sensors and which type is better. The CMOS stands for complementary metal-oxide-semiconductor, while the CCD stands for a charge-coupled device. The main difference in these two sensors is the way they process the analog to digital input, the light into electrons. When talking about CMOS vs CCD, we will first explain how they both work, and after that see which one will score better in the CMOS vs. CCD match-up.
So what’s the difference?
Before I list the pros and cons of each in this CMOS vs CCD comparison, let’s explain how they both work. CCD sensors process the light using sensors that are of very high quality in light sensitivity. The light is held in a photo sensor as an electrical charge, and then it’s converted to voltage finally to digital information. CMOS sensors work with the same CMOS technology for making chips for computer memory and processors. They have transistors on every pixel, and this way every pixel can be read individually. This kind of sensors are also called active pixel sensors and the functions of the image sensor and processing function on the same circuit, while CCD can’t do that. In the CMOS vs CCD comparison there are factors which we will go through in order to see the pros and cons of every sensor. Some of the CMOS vs CCD comparison factors include: power consumption, circuit integration, imaging performance and many more.
Pros and cons of CMOS vs CCD
In this comparison, CCD sensors deliver high quality and low noise images, while the CMOS sensors aren’t as good at this field. The CMOS sensors have several transistors for every pixel, while the CCD usually has only one or a small amount of pathways for all the pixels while converting to voltage. The factor that is very important in CMOS vs CCD comparison is uniformity: this represents the way different pixels will respond to identical illumination – the ideal would be if they would respond identically so they would be uniform. In CMOS every pixel does its own conversion so the uniformity isn’t as good. Also, in CMOS vs CCD, the CMOS sensor doesn’t have the blooming effect problem like the CCD one. The blooming effect occurs when the light source overloads the sensitivity and causes light bleeding to other pixels.
CMOS vs CCD: The price?
When we compare the prices of CMOS vs. CCD sensors, CMOS sensors are usually cheaper because they use the same technology that is used to manufacture chips for PC memory and processors, while the CCD needs its own manufacturing process. Even though CCD sensors are more expensive, CMOS sensors still need additional devices in order to reach the same quality as CCD. When choosing on a CMOS vs CCD, your final decision should depend on how much quality you need and if your budget is enough. In the CMOS vs. CCD race, the CCD still leads, but CMOS sensors are catching up.