CCTV is a short form for Closed Circuit Television. It refers to a surveillance system using cameras that send their signals back to a specific location. These video images can be monitored live, or stored for viewing later. You might have seen CCTV cameras generally being used to monitor stores, banks, and public buildings, etc. However, with the technology becoming more and more affordable and easier to use, many people are installing CCTV cameras even in their homes and businesses.
Many supermarkets and malls use a combination of security guards and a CCTV system to combat shoplifting. Smaller businesses may have only one CCTV camera installed in a prominent place so that shoppers know they are being watched. A retailer can review the tapes on a VCR later, or observe any shoppers that are behaving suspiciously and note the vulnerable areas in the store. The problem with recording and watching later is that some shoplifters can get away with stealing. On the other hand, if they return to same place, they can be caught.
In larger stores, the CCTV cameras are often get unnoticed. They can have high-resolution digital cameras mounted in smoke detectors, sprinkler heads, thermostats or clocks. It is also very popular to mount these cameras in ceiling tile domes (they are bubble-like and tinted so no one can see where the camera is pointed). From this point, a pan/tilt/zoom camera can swing about and follow someone around the store.
Types of Cameras
There are different types of CCTV systems available such as analog or digital, wired or wireless cameras. The methods used to operate them may be different, but the basic components and principle are pretty much the same. A CCTV system includes a camera, a lens, a monitor, and cables that carry the signal from one place to another for the wired systems. Many systems also use some form of video recorders to record the video footage.
The camera captures up the signal from the area being monitored using the lens. The lens used determines how far and how wide of an angle the camera can see. If the system is wired, the camera sends the signals through a cable to the monitor, and/or the recording device. If it is a wireless system, then the camera simply broadcasts the signal straight to the monitor itself.
The video cameras used usually do not look like the video cameras you see at your local electronics store. They are becoming smaller and more specialized for their security purposes. A standard CCTV camera may be in the range of 4 inches long by 2 1/2 inches wide with a lens on the end, or smaller.
The monitor used is often just a simple television set (often just a black and white set), but increasingly a PC or laptop is used. Most of the wired analog systems will use the simple television monitors, while digital and wireless systems are more likely to use computers as the monitors. By setting it up on a computer, you can actually see the images from anywhere using the internet.
Installing CCTV
Installing a CCTV system is generally very easy to do as long as you follow the instructions that come with it. The wireless systems are usually very portable and do not require much more than an electrical outlet and some software.
You might have seen some shopkeepers who have kept the monitors visible to the public so they can see themselves on a monitor as they enter a building. This way everyone knows for sure they are being monitored. It is also a way to reduce the practice of shoplifting.
If you are thinking of getting a CCTV system for your home or business, the first issue to decide on is what you can afford as the systems vary quite a bit. You also need to know exactly what you want to see in the monitor and on the recordings; examining both the scene and the quality of the images. Also, remember to buy one for the right reasons. Using a high-tech solution to solve a low-tech problem can result in wasted money and effort.
Analog & Digital TV
The CCTV cameras come in two types that is Analog and Digital ones.
Analog CCTV systems use one of two main conduits to transmit audio-visual information. The first, and most common, is a wired configuration. The second uses a wireless transmitter to connect to a receiver.
Wired CCTV installations run a cable or wire between the camera and the monitor. The image data is usually transmitted over a coaxial cable. The audio is usually transmitted over a simple copper wire or wires. The signal transmitted over these wires and cables is then fed in to a monitor or a set of monitors if the image needs to be visible in different locations. Analog CCTV cameras can also be routed to an image capture board on a computer to allow the audio-visual information to be viewed on a computer monitor.
Wireless CCTV installations are similar to wired. The difference is that a radio transmitter is attached to the camera. A radio receiver is then attached to the input on the monitor system or computer. Wireless systems are useful in a couple of situations. The first is when the distance between the camera and the monitor is too far to be practical for a cable run. Wireless CCTV is also good when cables aren't practical because of aesthetic reasons.
CCTV installations can also be digital. Digital CCTV often uses Internet Protocol (IP) cameras. An IP camera is a camera that contains the camera and hardware to convert the audio and video signals to a stream of packets that can then be transmitted over a local area network (LAN) wide area network, (WAN) or over the internet.
Digital CCTV has many advantages over analog. First, it can use existing wired or wireless internet, including Wi-Fi. Because of this, it isn't limited by distance. A CCTV camera can be set up in one city and have its signal transmitted easily to another city. Another advantage of digital CCTV is that a series of cameras can be routed to a wireless hub, thus minimizing the amount of cabling required for a complex installation
How Effective it is?
Video cameras, or closed-circuit television (CCTV), are becoming an increasingly familiar feature of modern life. Fears of terrorism and the availability of ever-cheaper cameras have accelerated the trend even more. The use of sophisticated systems by police and other security officials is particularly troubling in a democratic society.
The bottom line is that surveillance systems, once installed, rarely remain confined to their original purpose. Once the nation decides to go down the path of seeking security through video surveillance, the imperative to make it work becomes overwhelming, and the monitoring of citizens in public places quickly becomes pervasive.
One of the features of current surveillance practice is that the cameras are often installed in high-rent commercial areas. Crime may be merely pushed from high value commercial areas into less affluent residential areas. Video surveillance is bad deal for neighborhoods because running these systems will be expensive. The resources that could be better used for community policing.
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