CCTV cameras or Closed Circuit Televisions Cameras are used in both commercial and residential surveillance applications. They provide high-resolution images and record continuously and may be monitored remotely.
The first CCTV cameras were very expensive and required highly specialized and trained operators. One of the earliest was the Mole Richardson Company’s “ZB-26 Camera System” that came out in 1954. The camera was 49 inches long, 29 inches deep and 31 inches high. It weighs 310 pounds without the stand.
Modern cctv cameras are available from a number of manufacturers including Samsung, Panasonic, Bosch, Canon as well as other companies making 4mp and 5mp cameras with excellent resolution for both indoor and outdoor surveillance.
The most common cctv cameras are bullet or dome cams which may be either powered or unpowered, meaning they may have a built-in infrared light source. Fixed domes are fixed in one location and provide the highest quality image while the impracticality of mounting a fixed dome on an indoor ceiling means that pan tilt zoom (PTZ) cams are the most commonly used.
There are a number of camera types and styles that differ in how much light is required, what type of connection to the video recorder or monitoring device is required and other factors such as price. The most common cctv cameras currently in use include covert indoor dome cams, outdoor dome cams, fixed outdoor cams that have a light source, covert outdoor pinhole cameras and indoor/outdoor PTZ cameras.
More advanced DVRs allow for more than one camera to be viewed simultaneously as well as remote access from a computer or even an iPhone. Some models of cctv camera come with built-in SD cards that allow for storage of video directly onto the cctv camera, obviating the need for a DVR.
The recent advent of megapixel cameras has revolutionized cctv security and will eventually make 4mp and 5mp cameras the norm as bandwidth limitations disappear. These powerful new images can be zoomed, tracked and recorded and will provide such sharp image resolution that facial identification is now possible.
CCTV cameras may be fixed or pan tilt zoom. PTZ cams can move 24 degrees per second, while ordinary fixed dome cams generally just point straight out and cannot move at all. A lens is also required for each camera and brings us to the next consideration: type of lens.
There are a number of lenses that can be used with cctv cameras, including fixed focal lengths, varifocal and zoomable. Fixed focal length is common for indoor covert applications while varifocal lenses allow the user to change from a remote-distance setting to something closer such as an up close portrait. Zoom lenses can cover a broad range of distances and focal lengths.
CCTV cameras must be able to capture footage without too much noise, or at least with acceptable amounts of light – otherwise the images will appear grainy and unclear. Some indoor cctv camera models that come equipped with infrared (IR) illuminators which provide some light in low-light conditions may be used inside with acceptable results. But for most cctv applications, it is necessary to have a camera that operates as well as possible in many different lighting conditions.