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.
Why is this happening, and why is it essential to understand which sensor type is ideal for you?
Basically, the image sensor conversion technology you use determines the quality of the images you get. So, choosing the best option allows you to view high-resolution images instead of small and blurry ones.
In this article, we compare and contrast CCD and CMOS sensor image quality. We do this by elucidating some of the lesser-known technicalities as well as the advantages and disadvantages of each.
Our aim is to help drivers choose suitable sensor devices for their backup camera systems.
CMOS vs CCD for Backup Camera & Vehicle Safety Applications
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.
Image Quality Comparison
CCD and CMOS image sensors are different in how they digitally capture images. However, both technologies use photosites to convert light into electrons. When images are taken, the photosites are uncovered to collect photons and store them as electrical signals.
The major difference between CCD and CMOS is evident in the next phase of the process—where each photosite's accumulated charge is quantified. For instance, if you're using a CCD sensor backup camera system for your truck, the charge will be conveyed across the chip, where it is transformed into voltage, buffered, and relayed off-chip as an analog signal.
In contrast, a CMOS sensor has a charge-to-voltage conversion process for each pixel. These sensors also integrate noise correction, amplifiers, and digitization circuits that enable the relaying of the charges as digital bits.
While the images created by CCD sensors are of high quality and are low-noise, those generated by CMOS sensors are generally more predisposed to noise. This occurs because all the pixels in a CCD sensor can be dedicated to light capture. There is also more uniformity in the output (the conversion process for each pixel).
Advantages of CCD Sensors
The following are the major benefits of using a device with a CCD sensor.
- Higher image quality in low-light conditions: CCD sensor images are generally sharper than those created by CMOS sensors. These images are created at a highly pixelated resolution, even under low light
- More precise colors and less image noise: When light enters a CCD sensor device, it goes through a prism that splits it into red, green, and blue. The intensity of each color is then encoded, and the final images are low noise
- Suitable for high-end applications: Since the images created by CCD sensors are low in noise, highly uniform, and more sensitive to light, they have a linear characteristic, making them suitable for high-end applications
Advantages of CMOS Sensors
Now let us look at why going for a CMOS sensor would be ideal.
- Lower power consumption: CMOS sensors consume relatively lower power (up to 100 times less) than an equivalent CCD sensor
- Higher speed and frame rate: CMOS sensors have relatively higher frame rates than CCD sensors due to the fast reading of the pixels. This makes them ideal for image data analysis
- Lower cost: It is possible to manufacture CMOS sensors on ordinary silicon production lines. This makes them relatively cheaper to produce than CCD sensors
Applications for CCD and CMOS Sensors
Both CCD and CMOS sensors have unique characteristics that are suitable for different types of applications. In this section, we look at the main application areas for each to help you choose the right camera sensor for your needs.
CCD Sensor Applications
As we have already stated, CCD sensor devices are ideal for high-end applications. These detectors are used in imaging systems and microscopes, especially in the life science and medical fields.
Although CCD usage examples are too many to mention, the following are some scientific industries where they are widely used.
- Professional photography: The ability of CCD sensors to break image elements into pixels and turn the pixels into electrical charges based on light intensity has made them ideal for professional photography
- Scientific imaging: The application of charge-coupled devices has enabled the imaging of cells and also helped in advanced X-ray tomography systems
- Astronomy: When it comes to astronomy, CCD sensors are ideal since they can take images of enormous and far-away structures, such as celestial bodies. For example, these sensors have been used to take pictures of the Andromeda galaxy, which also shows that their application in this field goes back many years
CMOS Sensor Applications
The following are the main applications of CMOS sensors.
- Consumer photography: These sensors have been commonly used in modern digital cameras, including digital video cameras and digital CCTV cameras
- Mobile devices: CMOS sensors are ideal for mobile devices due to the relatively lower power consumption involved
- Surveillance cameras: Due to the low power consumption, low-cost production, and faster read speeds, CMOS sensors have been used in the manufacture of surveillance cameras. They are also commonly used in the production of backup camera systems
Choosing the Right Sensor for Your Truck's Backup Camera System
There are several factors to consider when selecting a sensor for your truck's backup camera system. For example, what is the intended application? What level of accuracy and precision are you going for? It would be best if you also considered the cost, sensor durability, response time, output type, and measuring range.
You can invest in different types of sensors for different applications for your truck based on your pricing needs. A few examples are temperature sensors, flow sensors, pressure sensors, capacitive sensors, oxygen sensors, throttle position sensors, parking sensors, and rain sensors.
These sensors perform different functions, such as monitoring the temperature, oil pressure, vehicle speed, coolant system, engine, or emission levels.
Contact Camera Source Today
When choosing a suitable sensor for your needs, it is best to consider the factors that we have outlined above. This ensures that you not only enhance the performance of your truck but also use these sensors in a way that will improve your safety and that of other drivers on the road.
At Camera Source, we sell various camera variants across our website and offer an excellent selection of products to fit all your backup camera needs and mounting requirements.
Contact us today to learn how we can improve your truck's performance by installing a backup camera system that integrates sensors that fit your intended application and cost considerations.
