A Guide to CCTV Technology
27/11/2019 in Security
Over recent years, CCTV camera technologies have seen some rapid developments, alongside the rest of the digital innovations. Although CCTV cameras are something that is often overlooked or taken for granted, their function makes them one of the best security measures used in construction site security.
CCTV cameras act as a deterrent towards potential trespassers or thieves and are a fundamental component of a security solution strategy.
CCTV technology consists of different aspects of hardware, software, storage solutions and even to the tiniest detail of the design. Read on as we discuss the different types of CCTV technology.
CCD or CMOS?
The sensor or imager found inside the front of the camera is typically either a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) chip.
Either CCD or CMOS chip is adequate, but each comes with their own constraints. For example, the CCDs using the ‘interline transfer’ method are cheaper but can display vertical streaks in the captured images around points of bright light. Whereas, CMOS chips can exhibit ‘rolling shutter’ problems, where warped shapes are displayed when it captures a fast-moving object.
Nonetheless, the chip type is only a small component to consider when it comes to considering the light sensitivity, camera design, resolution and other factors of a CCTV camera.
Types of Camera
CCTV camera comes in a wide range of shapes and types, which makes them uniquely suitable for a specific location or venue. In most cases, one type would be recommended over another depending on the use and the required capacity or view.
Commonly used for indoor and outdoor surveillance. The design of the dome shape makes it difficult to tell which way the camera is facing, which adds uncertainty and makes it a deterrent for trespassers.
This camera is ideal for outdoor use due to its long and cylinder shape. The strength of this camera lies in its ability to view objects from a long distance. Usually installed within protective casings, this camera is mainly used in an external setting as the design shields it against dust, dirt and other elements.
One of the more sophisticated camera types, the c-mount camera can support changes in technology and comes with detachable lenses. The lens can be changed to fit different applications. Using a specialised lens, this camera can cover distances beyond 40ft, whereas standard CCTV lenses typically are limited to covering distances of 35-40ft. A varifocal lens can also be used on this type of camera to capture ‘dead zones’ as it can capture and zoom without forfeiting its focus.
This camera type can record in colour and black & white and can operate during the day and night. The extra sensitive imaging chips in the camera means that it does not require inbuilt infrared illuminators, to capture clear video images in the dark.
PTZ Pan Tilt & Zoom Camera
This camera type coincides with having a live guard or surveillance specialist manually operating the security system. They can control the view of the camera by panning or tilting the camera. This camera also includes 200m IR night vision and an X36 optical zoom.
Otherwise known as thermal image cameras, they are one of the best 24-hour surveillance cameras used in large sites as it captures high-quality images – regardless of the time of day – and can cover distances up to 300 metres. This type of camera has small LEDs surrounding the lens to help pick up moving figures in complete darkness.
Industry-standard sensor sizes for analogue cameras comply with standard definition pixel sampling (720×576 pixels). These cameras also follow the standard aspect ratio of 4:3, which is the considered width:height for a non-widescreen video.
It is important to be aware that some cameras create lower resolution images; however, as CCTV cameras develop, as do the video capabilities – as larger imaging chips are used. This can facilitate megapixel sized image capture and at the same time, making these CCTV systems affordable.
High-quality photographic lenses should be fitted and have adequate light to capture images that have good resolution. Moreover, high definition (HD), which captures a 16:9 aspect ratio, has increasingly become more available in newer CCTV models.