| The image sensor is the camera component which | | | | at par in terms of performance. In fact, CMOS |
| captures light and begins the process of turning it into | | | | sensors are attractive in this space because of their |
| a digital image. There are two types of security | | | | much lower power requirements - an important |
| camera sensors: CCD (charge coupled device) and | | | | feature for devices which run on batteries. In the |
| CMOS (complementary metal oxide semiconductor). | | | | security camera world, I find that CCD sensors |
| Which of the two you choose depends on your | | | | outperform their CMOS counterparts in several key |
| application. | | | | metrics. |
| First a little background on each technology. | | | | The first and most important is light sensitivity. If you |
| Wtih a CCD sensor, every individual pixel's charge is | | | | need a security camera with superior night vision |
| transferred through an output node, which is then | | | | capabilities, CCD is the way to go. The CMOS |
| converted into an electrical signal. The signal is then | | | | cameras I have tested, with or without IR |
| buffered and sent as an analog signal. Because of the | | | | illumination, were almost completely blind in the dark. |
| pixels can be devoted to light capture, and the image | | | | Cameras with CCD sensors are very capable in low |
| quality is usually pretty high. | | | | light applications, and are terrific when coupled with |
| With a CMOS sensor, every individual pixel performs | | | | infrared illumination. If you need to record in low light |
| its own charge-to-voltage conversion, and the sensor | | | | situations, CCD is the way to go - do not even |
| also performs amplification and noise-correction. The | | | | consider CMOS. |
| sensor also includes digitization circuits which allow the | | | | The second factor to consider is image quality. In the |
| chip to output information in a digital format. Because | | | | security camera world, while both technologies are |
| of the complexity of this design, the area devoted | | | | getting closer, CCD still has the edge when it comes |
| to light capture is reduced. And because each pixel | | | | to image quality. This is because CCD sensors exhibit |
| must perform its own conversion, uniformity (thus | | | | less image noise than their CMOS counterparts. |
| image quality) is lower. | | | | So why would one consider purchasing a security |
| The production cost for both types of sensors are | | | | camera with a CMOS sensor? Mainly because these |
| similar, but CMOS sensors sometimes require | | | | sensors are more prevalent in IP Security Cameras - |
| additional support chips to optimize image quality. | | | | that is, cameras that are equipped with built in web |
| CMOS sensors are great for devices that require | | | | servers and communicate using the IP protocol over |
| speed and low power consumption, while CCD | | | | CAT5 cabling. These cameras tend to be very |
| sensors excel in image quality and low light | | | | affordable and are great for indoor applications that |
| performance. | | | | require web based video streaming. |
| While both CMOS and CCD sensors have matured a | | | | In conclusion, CCD sensors are the way to go for |
| great deal in recent years, when it comes to security | | | | outdoor applications, low light scenarios or when a |
| cameras, I prefer CCD for outdoor applications and | | | | higher quality image is required. CMOS sensor based |
| CMOS for indoor IP camera functions. Let me explain | | | | cameras should only be considered for indoor |
| why. | | | | applications with decent lighting conditions. |
| In the still camera world, CCD and CMOS are almost | | | | |