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The Technology Behind CCTV Systems


There is a lot that needs to be considered when choosing the right CCTV (Closed Circuit TV) camera for a project, from any physical constraints imposed by the site to technical requirements. As a consequence, there is a huge number of different CCTV ranges available on the market, catering to different needs, as well as constantly improving in terms of functionality, reliability, and performance. In this post, we are going to take a look at the technology behind CCTV security systems so that you can get a better understanding regarding how they work as well as the different options that are available.

CCTV Basics

CCTV is generally utilised for surveillance purposes, including safety monitoring, spying, and security monitoring. These solutions utilise one or several video cameras to transmit audio and video, via wired transmission or wireless, to a monitor or several of them. Over the past few years, the popularity of CCTV systems has surged, and the market has reacted accordingly, with more and more solutions released all of the time. There are many different types of CCTV cameras available now, and below we will take a look at some of the most common types.

The different types of CCTV cameras available

CCTV cameras can be categorised based on an array of different features, including whether they have any special functions, if they are able to move, the type of video recording device they offer, the type of connection to the monitor, the number of frames they can take per minute, and the type of images they capture. In regards to the latter, most CCTV cameras take video images both in colour or black or white. Nevertheless, there are cameras that now come with night vision, which means they feature special technology that allows them to view and record low light images.

Frames per second 

This is a feature that a lot of people are interested in when looking for the right CCTV system for their project. The vast majority of solutions available will capture 30 or more frames per second with ease. However, to record every moment of every day, you would need huge amounts of digital storage. Of course, it all depends on your reason for requiring CCTV. If you require it for monitoring purposes, you will find that one to six frames per second is more than enough. You may need something more substantial for a spying project, though.

Cameras with special accessories 

As mentioned, thespecial functions a CCTV camera has is another aspect to consider when looking at the different CCTV cameras available and the technology behind them. If you require a CCTV camera for specialist use, for example, if you need a CCTV system for spying because you want to catch out a criminal, you will be able to find small surveillance cameras on the market. There are also cameras designed especially for different outdoor and indoor uses.

Do you need to move the camera? 

There are some CCTV cameras that give you the ability to move the camera remotely. These are known as Pan Tilt Zoom (PTZ) cameras. The person controlling the surveillance of an area can use a wired controller or RF to move the camera. As you may have gathered by the name, you have the option to pan the camera from left to right and right to left, to tilt the camera up and down, and you can zoom in on an area as well.

How CCTV cameras record video images

Nowadays, most CCTV cameras either record video images via a digital video recorder or an analog tape. VCR tapes are generally used analog video recorders. If images need to be recorded for a long period of time, special security time-lapse VCRs will be used. These tape recorders can record both colour and black and white images for up to 960 hours. How many hours the video camera can record for depends on the number of cameras that are connected to the VCR as well as how many frames per second you intend to record. VCRs are popular because they are cost effective. They are also reliable and practical, offering a good solution no matter the project.

Digital video recorders work in a similar manner to VCRs. The difference is that they capture digital images from the CCTV camera. There are a number of factors that will determine how many digital images are captured, including the video compression used, the resolution the DVR saves images at, the number of cameras hooked up to the DVR, and frames per second recorded. You can get DVRs that are either hard drives connected to computer systems or standalone devices.

CCD Chips

CCD chips are used in most CCTV cameras. Most modern CCTV cameras use CCD chips that are a quarter-inch in size. Several years ago, the standard chips were half-inch diagonal, but demand drove manufacturers to create smaller versions. Nevertheless, the bigger the chip, the higher resolution and sensitivity that can be produced. Therefore, it is worth keeping this in mind, as it is often a balance between performance and size.

The connection

When it comes to the mechanics of a CCTV camera, the connection is undoubtedly one of the most important aspects. In general, you have two options to choose from, either a wireless connection or a fixed cable. Most people opt for the former option, as wireless gives you the freedom to place the CCTV camera virtually anywhere. To transmit video images to the monitor, most wireless CCTV cameras will use 2.4 Gigahertz frequencies. If you have more than one camera in a certain area, the frequencies may change slightly. Of course, all areas are different and have various operating limits, but you should find that 2.4 Gigahertz frequencies are substantial enough to transmit through walls and other obstacles.

With a fixed cable connection, a cable will physically connect the camera to the monitor. Cables come in various lengths, from 25 to 500 feet, and they are very similar to the standard home TV cables that are used.

Hopefully, you now have a better understanding regarding how CCTV works and the technology behind it. There are many different CCTV solutions available today to cater to the demands of modern surveillance. Understanding how CCTV works and the different options available will help ensure you have the right solution for your project.