What is a CCD and CMOS sensor in CCTV camera?
As a CCTV installer, we normally hear about CCD and CMOS sensors. If you are new to CCTV installation, when you buy your next camera, don’t forget to check its specification. You will see whether that camera is using CCD or CMOS sensor. In this article we will see the differences between CCD and CMOS sensors.
CCD Sensors or Charge coupled device
CCD sensor is made with silicon chipsets with receptors or photosites. These receptors or photosites collect light from the object and convert them to electrical charge. Once it is converted to electrical charge or current, it will be them displayed on a computer or any displaying device.
CCD sensor produces quite a lot of heat in the process of converting lights to electrical charge. In order to manufacture CCD sensor, it cost almost four times than a CMOS sensor. In earlier days CCD sensor were very popular as they were able to produce very clear video footage by photo generated charge from pixel to pixel.
CMOS Sensor or Complementary Metal
– Oxide Semiconductor
CCD converts pixel to pixel to charge and in CMOS, charge to voltage conversion happens inside pixel. In early days CMOS sensors were not able to produce sharp videos as CCD and they were less popular in CCTV application. CMOS uses negative polarity and positive polarity circuits and only one type of circuit is required at a given time, they use extremely less power compared to CCD sensors and this was seen as an advantage. If you are running cables for a long distance, camera requires less power are mostly preferred. CMOS sensors have shorter development cycle and this allows them to produce them cheaper however CCD was offering greater integration with longer development cycle.
As CMOS use one circuit to produce charge, when an object is in motion it may sometimes struggle to produce a good video footage. In contrast CCD covert pixel to pixel they were able to produce sharper video footages.
Modern CMOS sensors have improved a lot from early days. High performance is available in both sensors but far too big gap in price, still CMOS CCTV cameras cost far less to CCD and this makes CMOS ahead of CCD.