Frequently asked CCTV questions
The basic components of a CCTV system.
A Closed Circuit Television or CCTV surveillance system is a video system in which strategically placed cameras record and transmit to DVRs/NVRs. Only designated people have access to this footage.
- 1942 – With the Second World War still raging, CCTV technology developed rapidly. The first CCTV camera was developed by Siemens AG in Germany, to observe the launch of V2 rockets in the war.
- 1949 – Vericon, a company in the USA introduces the first commercial CCTV system. Very little is known about this product but we do know the video could not be recorded. Live view only. The same year George Orwell’s 1984 was published.
- 1968- The Invention of the well known Video Cassette Recorder (VCR) made its debut in the world of CCTV. New York is the first city in the world to install cameras along its main street.
- 1973 – New York Police Department (NYPD) set up cameras in Times square.
- 1980s – Although CCTV cameras have little impact on crime reduction, surveillance starts to spread across the US.
- 1985 – UK installs the first outdoor CCTV system in Bournemouth.
- 1996 – The first centralized IP camera, the Axis Neteye 200 released. Its capacity was limited to 1 frame second in CIF, with a resolution of 0.1MP (352*288)
- 1998 – Axis releases the Real Time Streaming Protocol (RTSP protocol) for HTTP. This encouraged 3rd party manufacturers to develop compatible software for handling and recording data.
- 1999 – The first decentralized IP camera was released. The cameras Linux system contained alarm, video and recording management functions. The first PoE (Power over Ethernet) standard was also introduced.
- 2001 – The 9/11 attacks in New York spurred the use of CCTV around the world. CCTV was seen as a keen tool to combat terrorism.
- 2005- The first IP camera with built in video content analysis was released by Intellio. The camera was able to detect a number of events like car theft, car travelling the wrong way, a person crossed a line or entered a predefined zone.
- 2013 – 5.9 million active cameras in the UK. 1 camera for every 11 people. British Security Industry Authority (BSIA)
Yes, the use of CCTV is legal in South Africa.
You have the right to protect your property and this can be done with a CCTV system implementation. CCTV monitoring is acceptable and even welcome in public areas, but is unreasonable to be spied on in your own home.
When you install CCTV cameras at your residence:
- Make sure you are transparent to those around you when installing a CCTV system. Inform your neighbours about the system.
- The CCTV cameras are only monitoring your property.
- If your CCTV camera is pointing directly at the neighbours property, reposition the cameras to avoid complaints and accusations of violation of privacy or harassment.
- If the cameras overlook the street, there is a sign informing people that they are monitored.
- The CCTV cameras are not monitoring areas where people could reasonably expect privacy.
- The stored information is not used for any other purpose other than protecting your property. So those videos of your neighbours skelmpie arriving/ leaving their house, will have to be deleted.
- If you record footage, do not keep them for longer than is necessary for the protection of your property.
- If your system captures information of an incident, retain that information to aid the SAPS investigations.
When you install CCTV cameras at your business, you must comply with the legal requirements regarding privacy.
- You might not be able to use your CCTV recordings if you do not comply with the law.
- Privacy legislation protects the rights of your employees and visitors.
- In terms of legislation, you are obliged to inform your employees and visitors that CCTV is in operation. This is usually achieved by posting signage at all entrance/exit points to your business. These premises are being monitored by CCTV surveillance.
- Your business has a legal obligation to protect the privacy and integrity of all who enter your premises. This includes staff, customers and suppliers.
- There may be no cameras in private areas. This includes changing rooms, bathrooms, toilets, showers etc.
An analogue signal is a continuous wave, denoted by a sine wave. It may vary in signal strength (amplitude) or frequency (waves per second).
The human voice is a prime example of an analogue signal.
a digital signal is a discreet signal that uses binary, 0s & 1s to communicate. Very similar to a light switch, it can be on or off. There are no other options.
DVR stands for Digital Video Recorder. Analogue cameras connect to the DVR. They connect by either using Coax cable or Cat 6 with video baluns. The analogue cameras are powered by 12v via a separate power cable.
The analogue video feeds received from the cameras are processed by the DVR. The DVR encodes and stores the footage on one of its hard drive/s in a digital format.
A DVR based system is always wired. That is a cable runs from the CCTV camera to the DVR.
The number of cameras that can connect to a DVR is defined by the number of channels available on the unit.
The most popular channel configurations for a DVR are 4,8,16 & 32.
NVR stands for Network Video Recorder.
IP cameras connect to the NVR. This can either be a wired or a wireless connection.
IP cameras encode the video stream at the camera and this information is transmitted to the NVR, where it is processed and stored.
NVRs security systems incorporate the newest technology to provide a feature rich system.
NVR based systems are more complex in their setup, but offer a more flexible option than a DVR based system.
Bullet cameras are named after their distinct cylindrical shape. They look like a bullet shell.
As one of the most common types of camera, they are a visible deterrent
The main benefits of utilizing bullet cameras are their installation and range.
Bullet cameras are weatherproof making them ideal for indoor and outdoor installations.
The lens of a bullet camera can either have a fixed or varifocal lens.
Bullet cameras are normally equipped with infrared LEDS, to assist in seeing in low light conditions.
Dome cameras get their name from their circular, dome shape. The camera is generally covered by a transparent plastic dome.
Domes can be used indoors or outdoors, just make sure the dome you get is rated for outdoor use.
Dome cameras are more discreet and blend in the surroundings better than bullet cameras.
One of the main benefits of a dome camera is that they make it difficult to determine where the camera is pointing.
A box CCTV camera or C-mount camera as they re also known, are cameras that have detachable lenses for different applications.
The box camera can be used both indoors and outdoors. If used outdoors it is recommended to use a camera housing , to protect the camera from the elements.
These cameras are often bulky and as such, act as a good crime deterrent.
PTZ is the abbreviation for Pan Tilt Zoom, and these cameras support that functionality.
They allow the user to control them remotely either through the DVR or Joystick controller. PTZ cameras can also be set up to to follow tours and patterns of the surroundings that it is monitoring.
PTZ cctv cameras are typically deployed to monitor wide open areas, requiring 360 degree view.
HDTVI stands for High Definition Transport Video Interface.
HDTVI is a video signal processing and transport technology used to transmit HD video across coaxial cables.
HDTVI is capable of transporting uncompressed HD video up to 500m on coax cable using analogue transmission techniques.
HDTVI technology was developed by the company Techpoint.
HDCVI stands for High Definition Composite Video Interface.
HDCVI is a video standard that enables users to transmit HD video over coax cable.
First introduced by Dahua in 2012, HDCVI’s capabilities have been expanded over the years.
IP cameras connects to a network in exactly the same way as any other standard network device such as a PC, tablet or printer.
Some IP cameras require the support of a Network Video Recorder (NVR) to handle recording, video and alarm management.
Others are able to operate in a decentralized manner with no NVR required, as the cam can record directly to any local or remote storage media.
IP cameras send images digitally using the transmission and security features of the TCP/IP protocol.
A 4-in-1 CCTV camera is a new hybrid format that allows one camera to be manually switched HDTVI, HDCVI, AHD and analogue. As long as the system uses a BNC connection and Coax cable, then the camera should work.
These cameras can be manually switched using a simple controller button on the camera.
A 4-in-1 camera will not work on an IP CCTV system.
A BNC connector (initials of Bayonet Neill-Concelman) is a miniature quick connect /disconnect connector used for coaxial cable.
BNCs are made to match the characteristic impedance of cable at either 50 or 75 ohms.
Originally designed for military use and has gained wide acceptance in RF and video applications.
An RJ45 connector is an eight pin standardized interface which often connects a computer to a LAN (Local Area Network).
The abbreviation, RJ45, stands for Registered Jack-45
A video balun enables the transmission of video using Unshielded Twisted Pair (UTP) instead of coaxial cable, to transmit the analogue v
The word “balun” comes from combining the terms balanced and unbalanced.
A video balun can either be active(powered) or passive(unpowered) and is required at both ends of the Cat 5/6 cable run.
HDMI stands for High Definition Multimedia Interface and is most frequently used for transferring both high definition audio and video across a single cable.
The HDMI cable is used to connect the NVR/DVR to the monitor/TV.
The HDMI interface is becoming the standard for the corporate and commercial markets.
Coax cable is made up of a metal shield and other components and engineered in order to minimize signal interference.
RG 59 Coaxial cable is for RF signals and low power video. The impedance of coax is 75 ohms.
RG59 Powax Cable allows installers to run both video and power to the cctv cameras, at the same time.
Category 6 (CAT 6) cable is a standardized twisted pair cable used for Ethernet connections and is backwards compatible with CAT5/5e cable standards.
Cable runs of up to 100m are supported using CAT6.
CAT 6 cable is used to connect IP cameras and NVRs, as well as hard wired network points.
Cat 6 cable can also be used instead of coax cable to transmit video signal. A video balun must be used both sides of the cable and it is recommended to run a separate cable to power the cctv camera.
Fibre-optic cables transmit data through flexible, optically pure glass fibres. The data is sent as pulses of light.
Fibre optic cable is used in CCTV security surveillance systems when there is a high chance of interference on the cable run.
Fibre optic is also the solution for long cable runs & high data transmission demands.
Fibre needs special equipment at both ends to convert the signals from electrical to light and from light back to electrical.
Most wireless networks in cctv are made using access points and stations.
APs (Access Point) and stations form bridges across wired networks. These links can span quite some distance depending on their power rating and the antennas used.
Camera manufacturers are fond of advertising cctv cams by the number of Megapixels (MP) they have. Pixels are small squares that are put together like puzzles or mosaics to build the picture.
A 1MP camera has a million pixels per square inch, a 2MP camera two million pixels per square inch and so on.
The more pixels, the better the image quality.
A MP usually denotes to an IP camera.
720 p HD is the original HD (High Definition) and has since been superseded by much higher resolutions. It typically refers to a 16:9 panel with 720pixels along its width and 1280 pixels along its length.1280 x 720 resolution.
1080p or FULL HD, offers almost twice the resolution of 720p. 1920×1808 resolution. Mainstream standard for high resolution.
4K or Ultra HD refers to a resolution of 3840x2160pixels , and is yet to replace 1080p.
8k is the lastest high- resolution standard that is only avavilable on a few selected premium display devices.IT has a resolution of 7680×4320 pixels and has twice the amount of pixels as that of 4K.
HD cameras are usually denoted by one of these example 720p or 1080p cctv camera.
720p is just less than a 1MP camera and a 1080p cctv camera is equivalent to a 2.1mp camera.
H.264, also referred to as AVC ( Advanced Video Coding) is an industry standard for video compression. This allows for the recording, compression and distribution of digital video content.
H.265 or High Efficiency Video Coding(HEVC), is more advanced than H.264. H265 allows for better compression leading to reduced file size and less strain on bandwidth.
H.265+, video quality nearly matches that of H265 but reduces the storage capacity and bandwidth that is required. Three key technologies help H265+ achieve this:
- Prediction encoding.
- Noise suppression.
- Flexible bitrate control.
A network switch is a networking hardware that connects devices on a network, by using packet switching to receive and forward data to the destination device.
A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer(layer 2) of the OSI model. (Open Systems Interconnection model)
Some switches also forward data at the network layer (layer 3) by incorporating routing functionality.
A network switch learns the identities of the connected devices and then only forwards data to the port connected to the device.
ColorVu is a technology created by Hikvision, that enables cameras to produce colourful videos even in extremely dimly lit environments.
This is achieved by two specific breakthroughs in hardware technology:
- Advanced lenses
- High-performance sensors.