What Youve Always Wanted To Know About CCTV

What is CCTV? & Why is there a Need for CCTV?

CCTV is the abbreviation for Closed Circuit Television. It is a visual surveillance technology system designed to monitor the desired surrounding environment and its activities. In recent years, the role of CCTV has grown to unprecedented levels. Originally used to deter crime and ‘anti-social behaviour’ such as minor offenses like littering, urinating in public and etc, CCTV now plays a more important role, assisting the police and security organizations in their investigations. Britain is currently the leading nation in implementing CCTV, most British towns and cities are moving to CCTV surveillance in public areas, housing estates, car parks and public facilities. Other countries are quickly following. North America, Australia and some European countries are installing the cameras in urban environments which a few years ago would most likely have rejected the technology CCTV is fast becoming an integral plan for crime control policies and social behaviour control theory in an effort to maintain ethical public behaviour and public order. It has become an icon for security and its presence is guaranteed to generate a sense of security and welcomed by many. This form of visual security can be sub-divided into analogue and IP (Internet Protocol) solutions.

What are the Benefits of CCTV?

  • Cut down on losses due to theft Increase employee productivity
  • Increase customer and employee safety
  • Provide 24/7 access to your system
  • Reduce the need for manual security (security guards)

Can CCTV Prevent Crime?

CCTV acts as deterrent rather than prevention to crime. CCTV deters ‘opportunistic’ crime, where people take advantage of a situation on the spur of the moment. The cameras are also creating a vastly increased rate of conviction after crimes are detected. Virtually everyone caught committing an offense on camera pleads guilty nowadays. Once people know they have been recorded on CCTV, they admit the offense immediately.

What Types of CCTV Cameras are there?

CCTV cameras are available in monochrome (black and white) or colour. The different types of cameras are Board CCTV cameras, Bullet CCTV cameras, Fixed Dome cameras or Vandal Proof cameras, Fixed CCTV Cameras (also known as Static cameras), Zoom cameras, PTZ (Pan, Tilt, Zoom) cameras, High Speed Dome cameras and IP (Internet Protocol) Network Cameras.

How to Choose a Suitable CCTV Camera for Your Needs?

Choosing the correct CCTV Camera that fits your digital surveillance requirements is very important. Below is a simplified set of guidelines when choosing the correct CCTV camera for your application

  • Location: Indoor or outdoor application
  • Requirement for day and night surveillance
  • The angle of view requirement. Wide angle coverage or a narrow field of view is required.
  • Budget

How does Focal Length Affect Angle of View?

Focal length is measured in mm. A short focal length (e.g. 3.6mm) represents a wide angle of view while a long focal length (16mm) represents a narrow angle of view.

What is Auto and Manual Iris?

Auto Iris lenses are lenses that are able to change the size of their iris in accordance to its surrounding light condition. When the camera mechanism detect that there is insufficient light, the lens will automatically enlarge its iris to accommodate more light in so it could focus properly and produce images that are not too bright or too dark to see. It will do the reverse when it’s too bright. For outdoor applications, where the light conditions are constantly changing, auto iris lenses are needed.For indoor applications, where light conditions are constant most of the time, a manual Iris lens would be sufficient for the application. Manual iris lenses provide an effective solution for applications where the surrounding environment and its lighting conditions are relatively stable. It gives the best performance when used with cameras that are equipped with electronic shutters.

What is the difference between Video Driver and a DC Driver in an Auto Iris Lens?

Auto iris lenses need a driving circuit to control and operate a motor to adjust the aperture range in accordance to varying light conditions. The driving circuit can be placed on either the camera lens or inside the camera itself. For video driver function, the control circuit is found on the camera lens. DC driver function camera has the control circuit built-in in the camera itself. Depending on the type of lens and camera you are using, you should always set it to the correct setting in order for the auto iris function to operate correctly

What is a Day and Night Camera?

Day and night cameras are cameras that are able to provide video surveillance even at low levels of illumination. A day and night camera displays a full colour image during the daytime but produces monochrome (Black and white) video images at times when the lighting is poor. The camera has a device that is sensitive to the surrounding light conditions and switches the camera between colour and black & white modes automatically. It is designed to increase its light sensitivity in poor lighting conditions and at the same time reduce noise level in the images. However, the day and night camera will fail if the illumination (Lux) level is too low

What is an IR camera?

IR is the abbreviation for Infrared. IR is a wavelength of light outside the human visible light spectrum and is generally offered at 850nm wavelength. IR cameras have image sensors that are designed to sense and process infrared light emitted from IR LEDs. Similar to Day & Night cameras, IR cameras turned to monochrome mode when illumination falls below a certain Lux. An IR camera differs from a Day & Night camera in which an IR camera is able to capture video images in absolute darkness with the help of infrared light source.

What are C and CS mounts?

It refers to the 2 different standards of CCTV camera lens mount. The difference between the two is the distance between the lens and the image sensor. C mount: 17.5mm, CS mount: 12.5mm. Cameras and lenses nowadays are generally CS mount rather than C mount. With CS mount cameras, both types of lenses can be used. However, the C mount lens requires an additional 5mm ring to be fitted between the camera and lens to achieve a focused image. With C mount cameras it is not possible to use CS mount lenses as it is not physically possible to mount the lens close enough to the image sense to achieve a focused image.

What is the term frames per second (fps)?

Frames per second (fps) relates to how many pictures a camera can deliver and the DVR can record in a second. Real time recording is about 25 fps. To calculate the fps per camera, take the total fps that the system could offer and divide it by the number of camera inputs. For example, a 100 fps DVR with 4 camera inputs would give u 100/4, 25fps per camera.

What is a CCTV System?

A basic CCTV system is made up of a CCTV camera, a video transmission system which sends video signals from the camera to a recording system such as a digital video recorder (DVR) which in turn sends the image to a monitor for display for viewing of playback purposes.

What is a DVR?

The old technology CCTV systems used the (now defunct) analogue method to record images onto VHS tapes from a multiplexer or similar device. This of course meant keeping a stock of tapes which needed to be changed frequently. The resolution of the recorded images was of very bad quality. Nowadays, the “new” technology (10 years old at least) uses DVRs (Digital Video Recorders) which process and stores video images digitally onto a Hard Disk Drive, therefore enabling long recording times with minimum maintenance and provides clear, high resolution images without degradation of image quality. Additionally, DVRs have real time image transmission and remote control capability over the Internet. IP CCTV with associated DVRs or NVRs is regarded as the most effective video monitoring system for any company that has a network or network capability.

What is IP-CCTV?

IP CCTV (Internet Protocol Closed Circuit Television), is a security surveillance system of IP Cameras andvideo servers which connects seamlessly with the Internet and Internet related digital services, including
Wi-Fi, Wi-Max, 3G or GPRS Access connection.

What are IP-CCTV Cameras?

IP CCTV cameras are similar to analogue CCTV cameras in features and functions but offer far superior picture quality. They do not transmit their images and sounds as analogue signals but as data. They also offer remote configuration of their settings, and on some models even the image sensor of the camera can be configured as required. IP CCTV cameras incorporate built in web servers which allow for live monitoring, recording and configuration across a computer network or the internet.

What are the benefits of IP CCTV?

  • Existing network infrastructure can be used, no long distance cables required.
  • IP security cameras can be moved with minimum time & effort, and cabling does not need to be replaced.
  • IP security cameras can be installed at any location, no matter the distance.
  • The same camera could be viewed or recorded simultaneously at multiple locations, and controlled on multiple security levels.
  • Recording could take place anywhere. An existing PC or Server could be used for a few cameras.
  • Any amount of recordings per camera can take place at the same time, at multiple locations for redundancy or off-site storage.
  • Bandwidth could be controlled differently for each camera.
  • Hard drive space can be shared across many systems for recording of video or data.
  • Audio or alarms can be connected to the same encoders which transmit the video.
  • Existing alarm system could be monitored from remote locations.

How Does IP CCTV Work?

An IP security camera image broadcasts the video images as a digitized signal over a LAN line (Local Area Network) where it’s then transmitted to a computer or server. Each camera is connected to the network via a transmitter/receiver unit that converts the analogue signal into DVD quality MPEG-4 or H.264 digital video for transmission over the network infrastructure. Depending upon the software used to manage the digital images, it can record, display or retransmit the images to anywhere in the world. The software package can allow for analysing data and selecting specific flagged items to watch out for. True IP-based digital surveillance uses CCD cameras that use signal processing that send packetized video streams over the LAN through a Cat 5/Cat 6 cable rather than a coax cable network, utilising greater bandwidth and standard TCP/IP communication. If security is an issue, full digital surveillance also offers the added advantage of data encryption opportunities to protect against image tampering.

What is IP CCTV Equipment?

IP-based network video solutions include equipment such as network cameras (IP cameras), network video recorders (NVR’s), video encoders/decoders and relevant alarm and monitoring software.

What is Video Motion Detection?

This is a type of based Video Analytics. It is able to see movement within the scene and can execute an action; like increase the record rate or email a picture etc… Basic Video Motion is not suited to external use as objects such as trees will cause it to trigger.

Can I view images remotely?

Yes, most DVR’s these days include remote viewing software. All you will need is a broadband line to which the DVR gets connected to.

What is Remote Monitoring?

Remote monitoring is the linking of your site to our Video Control room where they can see and control the CCTV whilst having the ability to issue warnings over a speaker system.

How is CCTV affected by the Data Protection Act?

Every commercial CCTV system should be registered with the ICO (Information Commissioners Office) and the rules and guidelines followed.