One of the most commonly asked questions by our customers is whether the camera system is CMOS or CCD. A common misconception is that CCD is better than CMOS, though in some camera systems this might be true, a carefully crafted CMOS chip can actually present a nicer image than the same camera with a CCD sensor. Before we get into why this is true lets first explain a little bit about each technology.
CCD (Charged Coupled Device) and CMOS (Complimentary Metal Oxide Semiconductor) are two different technologies for capturing digital images. Both types of imagers convert light into electrical charge and process it into electrical signals. With the CCD each pixel's charge is transferred through a single output node (most common) to be converted to voltage and sent off as an analog signal. This simple architecture has proven itself over the years to be the most reliable in quality because it is not using additional resources to make the conversion and can dedicate the entire pixel to image capture. CMOS on the other hand is much more complex in that each pixel has its own charge to voltage conversion and the sensor includes other processes such as amplification and noise correction, which in turn can reduce the area available for light capture. This CMOS conversion process is where chip manufacturers have the leeway to either make a superior sensor, or just a run of the mill. This is determined not only by the quality of the base chip itself, but more importantly on how the chip is programmed.
Though many vendors will try to sway you toward a product they sell over a competitor product because of the type of chip contained in the camera, the truth is that a good CMOS and CCD can represent the same high quality image. At Camera Source we manufacture our cameras with the the latest chip technology so we can be sure that our customers are getting the best possible image quality. Many of our cameras now contain our newest chip, which is a "Super CMOS" and allows us to get better overall light balance and color depth while improving the overall resolution. As a quick comparison here are the specifications between our CCD vs. our newest CMOS chip that we use in our GM cameras:
Resolution CCD = 512 X 582
Resolution CMOS = 780 X 420
TV Lines CCD = 480
TV Lines CMOS = 600
NIght Vision CCD = .3 LUX
NIght Vision CMOS = .1 LUX
In summary you can see that a well developed CMOS chip can have some advantages over a CCD sensor. The reality is that it is up to the manufacturer to effectively program the high quality chip with the desired functions, ultimately coming up with the best balance between day and night vision as well as a richly colored high resolution display. Since we control the manufacturing process we can ensure that the program contained on the chip will best serve our purpose in the automotive backup camera industry. Setting aside all the technical jargon we just talked about, let your eyes decide by comparing the pictures below:
Click here to see the Super CMOS
Click here to see the CCD