Camera Image Sensor Comparison
An outdoor security camera, like all cameras, uses an image sensor made up of many pixels which registers the amount of light and converts it to the corresponding number of electrons. The brighter the light, the more electrons are generated. There are two main technologies used for the camera’s image sensor.
These two types are the charge-coupled device, or CCD, and the complementary metal-oxide semiconductor, or CMOS. And despite being viewed as rivals in the camera industry, each type of image sensor really has its own strengths and weaknesses. So the better sensor depends on the situation it is to be used in.
CCD sensors were developed specifically for the camera industry while CMOS traces it’s beginnings to standard technology already in use in areas such as memory chips inside PCs. Today, modern CMOS sensors are advancing in technology and the quality is improving immensely.
The main benefit of a CCD sensor over a CMOS sensor is the higher light sensitivity. Being more sensitive to light means it can produce a better image in conditions where lighting is low.
The downside is that CCD sensors are more expensive and harder to build into a camera. Also, a CCD sensor uses much more power, almost 100 times more, than the equivalent CMOS sensor.
Recent advancement in technology is quickly making the CMOS sensor a close rival to the CCD sensor in terms of image quality. CMOS based cameras are lower cost because the CMOS sensors make it easier to build the cameras around them.
The CMOS sensors allow for much more integration possibilities and functions than the CCD could. It also has a faster readout which is important when you get into megapixels and require less energy and a smaller system size. You will find megapixel CMOS cameras much more than a megapixel CCD sensor simply because of the cost differentiation.
When it comes to megapixel sensors in cameras, the sensors themselves are about the same size or only slightly larger than traditional VGA sensors. This means that the size of each pixel is smaller. So while the megapixel camera can provide higher resolution and greater detail, it is less light sensitive since the pixel size is smaller and light reflected from an object is spread to more pixels.
