How CCTv Camera Works For Your Security

A CCTV system basically has four major constituents namely:

Among these gears, the camera is the principle part, since it is the one that gathers the images. The camera functions the same way that a normal camera does only if it is let alone to work.

The camera is offered with a motor, which assists it to shift the zoom parts. Once the camera has taken an image, it is taken for monitoring and then is recorded on a video tape or DVR.

How CCTv Camera Works For Your Security?

CCTV implies closed circuit television and it is taken into use in buildings and homes for surveillance purposes.

The best thing about CCTV systems is that they can employ two or more cameras. How do CCTV cameras work?

Well, they are just like the normal video cameras, however, they have various exclusive features. For example, they come with quality monitors that assist them to function on their own.

They also make use of wireless transmission to transfer images to monitors. Once your monitor has the images, it forwards them to the video tape or DVR.

A full CCTV camera system can include:

Cables (RJ45 or RJ59 Cables)
Video recorders (DVR or NVR)
Storage unit – typically Hard disk
A display unit (Optional, such as a Monitor)
Security Cameras (Analog or Digital Camera)

How Analog CCTV Camera works:

Analog CCTV camera captures images, and transmit continuous video signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity. i.e., analogous to another time varying signal. How CCTv Camera Works For Your Security

How IP CCTV camera works: How CCTv Camera Works For Your Security

Unlike analog CCTV Camera, IP CCTV Camera digitalizes the video signal at the camera level. The digital signal is a discrete representation of the analog waveform.

Which you can imagine those are very small discrete steps as the signal tries to approximate values.

Then the Network Video Recorder (NVR) keeps these digital signal, keep the record in the HDD.

The security of people and goods is a matter of increasing concern to society.

In order to safeguard what is most precious to them, restaurants, schools, factories and shops, among other activities and entities, are increasingly using the various solutions available. Aiming to better control procedures, infrastructures and facilities.

With the flexibility that is provided by its relationship with so-called new technologies, Video-Surveillance is one of the security solutions whose demand has increased in recent years.

However, if on the one hand the existence of cameras that collect images of a certain space. 24 hours a day, can please the departure, because we feel more safe. It is convenient to remember that this collection of images, and of personal data, can interfere with the individual rights, freedoms and guarantees of the citizen.

CCTV – What Does It Consist Of?

A CCTV system consists essentially of a set of cameras placed in strategic places that capture and transmit images to a video management system that allows. Among other things, the viewing / recording of these same images.

The use of a Video-Surveillance system controlled from a control center allows the visualization of all movements of a large surface where there is a large influx of people.

CCTV allows the visualization of these images after their recording. And in the detection of any event, know their causes, which helps to improve security with a preventive character.

In addition, the placement of visible cameras at strategic points deters any intentions of crime and provides visitors with a sense of security.

CCTV Solutions

There are basically three types of CCTV systems:

IP
HDTVI
Hybrids
Analog, with Digital Recording

Analog Systems With Digital Recording

There was a time when the technology of CCTV systems was fully analog and recording of images was done on VHS tapes.

At the beginning of the 90s of the

The first digital recording systems (DVR) have emerged that offer numerous advantages and far outweigh the benefits of classic analog recording systems, however, this generation of systems can not be considered pure IP as it converts the video signals analogue to digital formats, which are later stored on a hard drive and can be accessed remotely over IP.

This technology has some advantages and disadvantages when compared to the latest systems based on IP technology.

Advantages of Analog Camera Based Systems

Low cost – Analog cameras usually have a lower cost than IP cameras.
Larger variety – There is a wide variety of models / types of analog cameras.
Compatibility – Ability to fully integrate cameras from multiple manufacturers

Disadvantages of Analog Camera Based Systems

Installation Costs – The cabling networks of these systems have higher costs and are limited to the maximum transmission distance allowed by the coaxial cable, because there is degradation of the image as a function of the distance traveled.
Difficulty of Expansion – The installations of systems based on analog cameras are limited to the number of cameras allowed by the DVR, and sometimes it is necessary to replace the existing recorder.
Lower Resolution – The scanned analogue image rarely generates a setting greater than 0.4 Megapixel. IP cameras have a resolution of 3 Megapixel or more.

How CCTV Works

Closed Circuit TV Camera, typically abbreviated as CCTV camera, comprises at least one camera transmitting data to a monitor or video recorder.

The data transmitted can either be video and audio, or video only. A CCTV camera must never be mistaken for an ordinary TV.

An ordinary television receives publicly broadcasted contents while a CCTV doesn’t. In everyday use, CCTV cameras are fitted on buildings, gates, and other structures purely for surveillance purposes.

The closed circuit system can either be used to monitor live proceedings like in a supermarket or documented for later reference. How CCTv Camera Works For Your Security

CCTV Camera Components And Their Working

The complete closed circuit TV system (CCTV system) consists of:

Cables (RJ45 or RJ59 Cables)
Video recorders (DVR or NVR)
Storage unit – typically Hard disk
A display unit (Optional, such as a Monitor)
The Security Cameras (Analog or Digital Camera)

1. Security Camera: How CCTv Camera Works For Your Security

Security camera captures the video of the source. An opened aperture at the front of the camera captures light stream through the camera lens.

The light stream is captured by a digital chip that is fitted inside the camera and is converted into the continuous stream of images.

The camera records the signal to be transmitted either through cables or wirelessly. The distance between the camera and the object is determined by the camera lens specifications.

Infrared Light Emitting Diodes (IR LEDs) are used as sensing devices in CCTV cameras. The light sensor is used to detect the ambient light level i.e. it detects the brightness of light it receives and transforms it into a numeric value that tells the percentage of brightness.

Due to the digital technology employed in data recording and processing, it is possible to receive sharp images, clear audio and fewer signal interferences from the wireless cameras.

This type of camera is often referred as “IP Camera” (we will talk in more details later)

2. Cables: How CCTv Camera Works For Your Security

The cables are just the wires that are used to connect different equipments like CCTV camera, monitor, recorders, modem etc. in a CCTV camera setup.

For CCTV cameras, the cables used are either RJ45 or RJ59 cables. These cables, if RJ59, may include BNC connectors to connect camera to video output (such as Monitor), power connectors etc. As for a RJ45 cable, cat 5e or cat 6 cables are most frequently used in CCTV camera setup.

3. Video Recorders

When a CCTV camera sends video signals that might be useful at a later date it must be documented somewhere.

There are two main types of recorders namely digital and analog recorders. Nowadays, Digital Video Recorders (DVRs) or Network Video Recorders (NVRs) are used to record CCTV camera footage.

4. Digital Video Recorders (DVR)

Digital Video Recorder, or DVR, stores the transmitted video images in either stand-alone devices or an external storage backup system.

The basic working principles of analog recorders and DVRs are closely related except that digital video recorders document the data in digital format.

The video data is coded, stored and processed at DVR only.

DVR can be easily accessed through a web browser, or CCTV centralised software, or a mobile application.

The number of images recorded on a digital video recorder depends on the following factors:

The DVRs image resolution, bitrate, etc
The video image compression technique used.
The total number of CCTV cameras linked to the DVRs
The desired number of frames to be recorded in every second

5. Network Video Recorder (NVR)

The NVR work same as DVR, only the difference is the inputs. Unlike DVR, the NVR takes its input from a network rather than the direct connection to a video capture device.

NVR always works with IP camera. The video on the NVR is coded and processed at the IP camera and is stored on it for remote viewing.

Furthermore, some additional functions like compression or tagging with Meta data can be done on NVR.

The surveillance systems with NVR can be either wire, or wireless (By the way, wireless NVR works well theoretically, but in reality, wireless NVR is not the main stream because of the stability issue with the wireless signal), and can also be easily accessed through a web browser, or CCTV centralised software, or a mobile application.

6. Hard Disk

The Hard disk is a storage device which stores the video captured by the security camera so that it can be used later. These CCTV hard disks are fitted within the video recorders.

To view the video recordings on the hard disk, you can directly connect the DVR or NVR to monitor.

Note that you should always choose those “surveillance grade” hard disks, which are designed to run 24×7 and made more durable compared with normal computer hard disks.

7. A display Unit (Monitor)

The display unit, or a monitor, takes the video image from DVR, or NVR and outputs it on the screen. You can see the video or image on screen that is been captured by the camera.

The monitor can be a monochrome screen or a colored screen. Nowadays, High Definition (HD) colored LED monitors are quite commonly used to watch the videos.

Different Categories of CCTV Cameras

There are many ways to categorised CCTV cameras. We will use the following subheadings to classify CCTV cameras systems:

1. Wired and Wireless CCTVs

All CCTV systems have to record and transmit the documented picture. Based on transmission mode there exist two categories of CCTV cameras;

Wired cameras, those that transmit their video signals via a cable
Wireless cameras that require no signal transmission cable

A) Wired CCTV

Systems typically use a communication cable similar to the one feeding antennas (RF cable). One major drawback in using wired CCTV cameras is that as the transmission range increases more than 300 meters, the signal may become weaker.

To manage the problem, one should consider using appropriate networking cables (for example Cat6), as well as adding switches on the halfway, or use high-quality signal boosters.

In a multichannel closed circuit TV system, several cameras are strategically placed at various locations and can be designed to be interconnected through a multi-viewer circuit to allow close monitoring from a single computer or screen.

For a small house, to have non-messy interconnection, a multichannel system can use wireless CCTV cameras. Such cameras would negate transmission cables as only power lines would be a must, hence leaving behind a neat finishing.

The wireless CCTV camera communication can cover 20 meters or even more. This might make such cameras ideal for complex structures.

But, the big drawbacks are the strength of the wireless signal, which is determined by the infrastructure of how you design your wireless network. Scientific research has already shown that wireless signal can drop by up to 90% if it goes through a concrete wall with steel inside.

This can become a big issue when connecting the wireless CCTV cameras – unstable connection, hence loss of video records, is simply can’t be accepted for surveillance CCTV cameras.

B) Analog CCTV Camera ( Uses DVR) or Internet Protocol (IP Camera) (Uses NVR) CCTV

Leaving technologies behind, to normal users, the primary difference between analog and more digitalized IP camera is the video image quality, in term of sharpness and video image resolution. The IP cameras come under wired or wireless category of CCTV camera.

IP cameras use NVR and can provide a much higher image resolution (megapixels) than the conventional analog TVL CCTV cameras.

IP cameras are therefore preferred conventional analog TVL cameras due to the following reasons:

Provides much sharper images than analog cameras
IP digital signals are not so prone to signal interference
IP cameras are easily accessible through a Web browser.
They require less amount of cables to be installed: a POE IP cameras require only one networking cable connecting it to the video recorder.

How An IP Camera Operates: How CCTv Camera Works For Your Security

Internet Protocol Cameras (IP Cameras) provide surveillance function but through a digital network.

These cameras rely on the computer network-both in sending and receiving information.

The connection can either be through the wires (cat5e or Cat6) or Wi-Fi.

Since the data exchange is through the internet, the operator doesn’t need to be in a fixed location all the time.
When you connect an IP camera to network, and you can monitor your premises from any location.
You just have to open the web browser on Computer, enter the Static IP address / or DDNS domain name of the camera, to watch the live feed; or you can just open smart phone application to do so.
Though the IP cameras are tiny, they have high resolution and even give a high definition.
These new-age IP cameras can be remotely accessed, controlled, and repositioned as desired. You don’t have to be physically near the camera to rotate it to a given angle.

Furthermore, some modern IP cameras are quite responsive to heat movement or sound. Therefore having been fixed in a room. The camera will only go live on the recording when there is an activity to be recorded.

The IP camera won’t need to be adjusted to the direction of the incident; due to its sensitiveness to sound, it will automatically detect the origin of the sound and rotate, tilt and record the event.

Wide Dynamic Range (WDR) is also an important function for IP cameras. This function helps to digitally enhance the image quality in some certain scenes. To cope up with difficult lighting conditions. They can differentiate objects even in low light situations.

Typical Uses of CCTV Cameras

1. Crime Detection or Prevention

The chief use of CCTV cameras is for surveying an area with the aim of detecting and preventing crime. Most car parks, supermarkets, major stores and other public places fit surveillance cameras for this reason.

2. Industrial Use

Monitoring of critical industrial processes mainly employs CCTV cameras and not human beings. This is very true in the case of chemical based or nuclear-based industries.

For example, thermo-graphic CCTV cameras find unique application in nuclear fuel plant.

3. Traffic Use

The main cities do experience huge traffic congestion or accidents. Closed circuit cameras can then be fitted along the streets so as to automatically record any accident or indicate the roads with more traffic jam.

4. Used In Schools: How CCTv Camera Works For Your Security

In many developed countries. CCTV camera system is used to keep a check on students who are prone to vandalizing school properties or those who find pleasure in bullying their colleagues.

5. Transport Industry

Surveillance cameras are also used in the transportation services.

For example in an underground train, through the utilization of a surveillance camera, an operator can trace the passengers’ movements so as to know when to open or close the doors.

6. Monitoring Employees: How CCTv Camera Works For Your Security

Major organizations and companies use CCTV cameras to keep track of employees in different sections. The cameras would send video signals for each process. Through that, it is possible to pinpoint for a delayed stage of production.

CCTV cameras are sometimes prone to vandalism hence rendering them ineffective. To overcome this problem, manufacturers, have come up with cameras which are resistive to different things like: