CCD Security Camera
When researching security cameras for your home or business, you might come across two different types of image sensors used to produce the digital images when recording: CCD and CMOS. CMOS and CCD security cameras utilise different technology and therefore each has its own distinct pros and cons.
What are Image Sensors?
An image sensor is located just after the lens of a camera. The light that passes through the lens lands on the sensor; the sensor then collects the light and converts it into voltage electrons. This is commonly known as image pixels, which are then converted into a digital signal using a convertor. CCD and CMOS are two separate types of image sensor used in this process.
CCD vs. CMOS
CCD security cameras (Charged Coupled Device) work by light hitting the image sensor; this is then converted to an electrical signal. This information is then transferred one pixel at a time to an image processor, where it is then converted to voltage. This voltage is sent from the chip as an analog signal.
What differentiates CCD sensors from CMOS sensors is that CMOS sensors begin to process the image immediately, whilst CCDs require an extra step to process the image. This results in more time and energy being needed, but the upside is that because each pixel captures light, the CCD sensors offer a higher quality and clearer image.
CCDs differ from CMOS in that they generally use global shutters rather than rolling shutters. A global shutter processes an entire image at once by exposing the full frame, the result is the sensor absorbs an equal amount of light and this improves image quality.
Some of the Benefits of a CCD Camera:
There are distinct strengths and weaknesses to both CCD security cameras and CMOS. But opting for a CCD sensor will provide you with the following:
- The focus of CCDs is superior image quality, low-noise and flexibility. Therefore if you’re looking for a security system with high-end imaging, then this is the choice for you.
- CCD sensors can offer sensitivity advantages over CMOS, especially when working with higher temperatures. CMOS often require cooling in these scenarios.
- CCD sensors have been in production for a long duration of time and as a result are more mature than CMOS.
- Lenses have been developed to give CCD sensors higher sensitivity, which minimises the lost incident light.
However, CMOS technology has improved a lot since the 1990s, and the old days of fuzzy CMOS images are gone. The clarity of CMOS sensors has improved, as well as resolution – there are CMOS that can reach AHD (Analog High Definition) of 720p or 1080p. Nowadays most security camera models are CMOS cameras. In fact, cameras today are not usually labelled as CCD/CMOS anymore.