What is Closed Circuit Television (CCTV)?
CCTV or Closed Circuit Television refers to a visible or covert video system intended for only a limited number of viewers. In Closed Circuit TV (CCTV), the picture is viewed or recorded, but not broadcast. It was initially developed as a means of security for banks and casinos; however, today it has been developed to the point where it is simple and inexpensive enough to be used with Home Security Systems, and for everyday surveillance.
More specifically, CCTV is a television transmission system in which live or prerecorded signals are sent over a closed loop to a finite and predetermined group of receivers, usually as scrambled radio waves that are unscrambled at the point of reception. CCTV takes numerous forms and performs a wide range of functions ranging from image enhancement for the partially sighted to the transmission of pay-per-view broadcasts. Although cable television is technically a form of Closed Circuit TV, the term is generally used to describe systems with more specialized applications than a standard broadcast or cable television. Such specialized systems are not subject to regulation by the Federal Communications Commission (FCC); however, Security Cameras using scrambled radio waves are in fact subject to common carrier tariffs and FCC conditions of service.
What is CCTV’s primary function?
CCTV is most commonly used for surveillance. Security Cameras are now universally featured in many public and private institutions, from a correctional facility to the convenience store. In prisons, reduce the costs of staffing and operating observation towers and make it possible to maintain a constant watch on all areas of the facility. CCTV has become so much less expensive over the years that both large and small stores are able to install cameras as a deterrent against theft and robbery, a practice, which municipal authorities have adopted as a way of curtailing crime in public housing and even on city streets. In many areas of the country as well as in Europe, Security Cameras have been placed in highly crowded public areas as a security measure against terrorism.
What are some other common uses of CCTV?
CCTV has many industrial and scientific applications outside of the world of surveillance. Electron microscopy, medical imaging and robotics are all common uses of CCTV, however, the term "Closed Circuit TV" does in fact most often refer to security and surveillance camera systems. Other common forms of CCTV include live on-site video displays for special events such as various conventions, arena sports and concerts as well as pay-per-view telecasts of sporting events such as boxing and pro wrestling. Also a common user of CCTV is "in-house" television channels that broadcast to very small and specific receivers such as in hospitals, airports, racetracks, schools, malls, grocery stores, and municipal buildings.
What are the different CCTV model types?
In-Line: These are the most simple model and thought of as the traditional CCTV. The monitor or video display is mounted over the camera.
Out-of-Line: These models have a camera unit and generally use a television as their display. They are not "portable" in the sense that the camera unit is a full size camera and the devices should be used on a desk. The camera unit would sit beside the monitor, or "out of line."
CCTV's that use Computer Monitors: These CCTV’s connect simply to a computer monitor. They are not interchangeable with a television, but are made specifically for integration with a monitor. They offer access to the print material, the computer application, or both using a split screen function.
Portable: These CCTV’s can be considered portable in that you do not have to use a television with them. You can purchase a display that will allow you more freedom in how it is used.
Hand Held: A Hand Held CCTV is not always portable. Most models depend on the use of a television unlike the purely portable CCTV’s. Generally, the ability to write using a hand held or Portable CCTV is not as functional as with In-Line or Out-of-Line models.
What are the different types of CCTV lenses,
and how does one choose which lens to use?
There are four types of lenses for CCTV use: Fixed Aperture, Manual Iris, Auto Iris, and Zoom. If the area you wish to observe experiences infrequent changes in light, use a manual iris lens, which can be adjusted for light only by hand. If the area the Security Camera will be observing experiences frequent changes in light, use an auto-iris lens. These lenses adjust to light changes automatically. Auto-iris lenses come in Video or DC, and cameras generally support one format or the other. Be sure your lens matches the camera. To perform close-ups, get a zoom lens, manual and motorized zoom lenses are easily available from most retailers.
Here we have a list of CCTV systems companies in USA
|Company name||Primary business area||Primary coverage|
|Arecont Vision||IP networking products||Global|
|Grandstream Networks Incorporated||IP networking products||United States of America (USA)|
|Visionhitech Americas, Inc.||CCTV||United States of America (USA)|
|DSX Access Systems, Inc.||Access control||Global|
|IQinVision||CCTV||United States of America (USA)|
|Lenel Systems International||Access control||Global|
|Network Video Technologies||CCTV||Global|
|Network Webcams US||IP networking products||United States of America (USA)|
|Vigitron, Inc.||Transmission systems||Global|
|1st American Investigative Agency||Digital video recording||United States of America (USA)|
|21st Century Locks Ltd||Access control||United States of America (USA)|
|2D Electronics||CCTV||United States of America (USA)|
|2M CCTV||CCTV||United States of America (USA)|
|3rd Eye Surveillance Systems||Digital video recording||United States of America (USA)|
|911 Security Cameras||CCTV||United States of America (USA)|
|AATEL||CCTV||United States of America (USA)|
|Aboundi Inc.||IP networking products||North America|
|Access Control Servers||Access control||United States of America (USA)|
|Access Security Corporation||CCTV||North America|
|Access Specialties, Inc.||Integrated security||United States of America (USA)|
|Access Systems Integration, LLC||Integrated security||United States of America (USA)|
|Accordance Systems||Digital video recording||United States of America (USA)|
|Accu-Tech Corp.||Access control||United States of America (USA)|
|ActEyes Technology Inc||CCTV||United States of America (USA)|
|Action Bullet Resistant Corp.||Access control||United States of America (USA)|
|Active Response Monitoring||Central monitoring systems||United States of America (USA)|
|ActivEye, Inc.||CCTV||United States of America (USA)|
|Acuity-vct||CCTV||United States of America (USA)|
source: sourcesecurity & brickhousesecurity