Solid-state cameras (analog or chip) have been around since the mid-1980s. In their early versions, the only improvements offered over tube technology was no image burn on the monitor or camera, and they lasted longer. The word “tube” was then replaced with the term “imager”. However, to precisely capture the single shade and hue per pixel, each transistor required an optical lens. In the early days, these were literally glued in place. This time-consuming process accounted for both geometric distortion and low sensitivity. To a larger degree, it also accounted for the camera’s large price tag.

A breakthrough occurred when Sony Corporation perfected a process in which the lenses on the transistors could be fused at the time of chip manufacture. This improved performance across the board and speeded up production such that the cameras could be mass-produced. With mass production also came a radical reduction in price. There was one period of time when the 1/2-inch imager was the most current, so Sony claimed that every such camera was a “Sony” because they were producing them for all manufacturers. At the time, there was also a rapidly growing consumer market for the now indispensable home camcorder. However, although picture geometry and life span had improved, there still was no major difference between the chip and tube camera. When CCTV was deployed both indoors and outdoors, it was not unusual to find chip cameras indoors and tube cameras outdoors. However, the greatest benefit of the new chip technology has been the size of the devices. Microtechnology has made them so small that the medical industry uses cameras that can be swallowed for noninvasive diagnostics.

In the world of CCTV, the first glimpse of digital video’s potential could been seen with the arrival of the “quad”. This product resulted because of the increasing microprocessor speeds. Four analog camera signals were digitized, which allowed the processor power to use the conventional image and create a new single camera signal that was made from four precisely positioned cameras. These positions were quadrants of the overall screen display, hence the term “quad”. Although the term “quad multiplexer” was used initially, the term “splitter” became a better choice of terminology. Screen splitting in analog technology had been around for years.

Quad splitting clearly was a tremendous milestone. It resolved three major issues. First, the number of monitors was reduced; before this time, there had always been a ratio of one camera to one monitor. The second issue was synch. Because the signals were digitized, the cameras did not need to be synchronized to one another because the phase and timing of the analog signal were converted to digital “words”. The third issue was recording. Until this point, recording of multiple cameras required video switching from camera to camera.

Although this process worked (and was used for many years), much was lost during the long time intervals before any specific camera was again recorded. Because security incidents may only take seconds to occur, a recording of the whole incident might easily be lost. The choices were either switching recorders or using separate recorders per camera, which at that time, was a very expensive and high-maintenance proposition. Now, four cameras per recorder were to be simultaneously used.

Simplex refers to recording 8 or 16 cameras to a single tape, but only being able to view them in this manner upon tape playback. In real time, the simplex device acts as a switcher, sequencing through each camera scene. Duplex offers the multicamera viewing in real-time operation as well as recording. Initially, users saw this duplex device as a means to do away with switchers and multiple monitors by simply displaying 16 cameras on the screen. Viewing 16 cameras, no matter how large the monitor screen, was difficult for the user. Even if the quality issue could be overcome, the human eye has yet to distinguish irregularities within a view of 16 real-time activities.

The main element was the recording aspect. The ability to record 16 cameras to a single tape, along with the ability to extract any one of the 16 on command, was an incredible breakthrough. However, like all new developments, applications were left in the hands of many ill-equipped individuals, who did not understand video and how it operated, let alone how the multiplexer worked. Therefore, hours could be spent reviewing video tape in an effort to observe a single, brief incident because there was not a simple and easy way to review the video tape until the development of the digital camera.

Since its invention, many of us have believed that the video camera is just like the human eye; but in reality, it is not. First of all, there is a contrast between the eye versus camera. The camera presents a two-dimensional, “flat” image, unlike the three-dimensional image of the human eye. To compensate for the lack of depth dimension, video uses shades and hues to create the illusion of depth.

This explains why camera placement is so crucial. Height provides angularity, which helps in the “illusion of depth”. If a camera was mounted at the same height as the eyes of a six-foot man looking straight ahead, not only would the illusion of depth disappear, but anything in the foreground of that view would effectively block anything behind it. As we know, this does not occur with human vision.

Analog video technology simply could not overcome multiple hindrances that we take for granted with the eye. For example, if we look out a glass window or a door in daytime, except only under intense sunlight, our eyes generally enable us to clearly discern and identify people or objects outside. In lieu of any compensation, however, a camera will “key” to the typical sunlight and the object or person will only be a dark shadow if positioned between the light source and the camera. Furthermore, on very sunny days with objects or persons adorned by light colors (reflecting light), the camera is impeded by an excessive “white level”. Clearly, a camera is not the same as the human eye. During the long period of analog technology, there were simply cases where the camera could do nothing for us.

It was because of this digital process that another obstacle was conquered. Camera sensitivity also was dramatically improved by DSP. For most of its history, the standard camera operated within the visible light spectrum. Except in the absolute cold of space, all solid objects have varying temperatures associated to them, based on the color and composition. This translates to “heat”. In a video scene, the infrared spectrum, immediately adjacent to the visible spectrum, contained nearly identical information. However, it was unusable. The analog video scanning system processed visible light levels but analysis of that light would have required a level of technology that simply was not there.

This is now the era of high-speed, miniature, and relatively low-cost microprocessors. The camera is redesigned and these processors are introduced into those designs. Analyzing each pixel digitally, this mirror information in the infrared could then be translated to matching shades of gray as in the visual spectrum. Black-and-white charge-coupled device (CCD) cameras are now functioning down to the levels of those very expensive specialized tube cameras previously mentioned. The quality of the solid state pixel is what determines how a usable picture may be produced. The good news is that this is now standard performance with most quality CCD cameras, even those tagged as “utility grade” in the $250 price range. Right behind them are the quality color CCD cameras that use digital analysis to provide full video into light levels never attained before. Missing details are filled in because of statistical analysis.

Regarding the camera, there are other benefits to this digital process. Once the analog signal is converted to digital data, many things are possible. While in this digital state, it is now commonplace to insert text onto the video image, thus enabling the camera to identify itself. Previously, this was an expensive process that was performed in the monitoring center. Also, the entire point of a person viewing a video scene is to detect something happening that should not be happening. Cameras are often placed to view conditions, where nothing is happening or moving. When something does move, the quiet state is changed, as is the light level striking the pixel in the scene where movement is present. DSP has made it possible to allow a camera to be an alarm detection device. This is based on a user-defined number of picture elements displaying a defined level change from normal during digital analysis. With DSP, all these new advances have been used before the signal even leaves the camera.

Cameras with their own internet protocol address are gaining in popularity. They can plug into any wall jack that is connected to the local area network (LAN). Now, with the proper software, your LAN can serve as your CCTV network. However, as with any new technical advance, there is much to be considered. CCTV users are accustomed to certain operational techniques and levels of performance—not the least of these are monitoring centers with multiple screens, all displaying live video, as each system requires. This live video is, in fact, full-motion. Finally, the displayed video is of the best quality resolution.

Here is how these new LAN cameras operate and what would be needed to meet all traditional expectations:

In addition, two generations later, digital recorders have now arrived.

All of these new functions are truly fantastic when compared to nearly 50 years of CCTV technology. To best understand the magnitude of what digital recorder/servers have done for CCTV, consider this: All traditional analog systems were built with “home run” topologies to central monitoring points. This meant that if a system contained 120 cameras, there were 120 cables converging on a central point, along with all of the massive costs associated with such a network. Digital recorder/servers can be placed at any concentration point as long as that point can plug into the LAN. This is both a clear technology improvement and cost reduction that will present huge operational and cost benefits over the short and long-term life of a CCTV network.

There is a growing demand for remote monitoring and playback capabilities of cameras. A security manager who is traveling may be notified of a serious incident at a particular facility. Using the appropriate technology, it is now possible to remotely access a building’s network video system to view the video or a recording of the incident. A network camera can connect directly to a computer network [2].

Now many security companies offer state-of-the-art 24/7 video monitoring services where recording and viewing of many cameras are conducted off-site, usually hundreds of miles from where the cameras are located.

Many security mangers have programmed their cameras to monitor certain areas at certain times. A security officer should never attempt to alter or change the settings of the programmed recordings. Camera systems provide a deterrent to theft and crime if used properly; however, even with all of the technological advancements in recent years, cameras provide a greater service in the investigation of an incident after it has occurred.

As federal agencies, cities, and local police departments spend more money on vast networks of closed-circuit surveillance cameras, some critics are wondering whether these systems are an effective way to stop crime and a good use of resources.

In a 2011 column, Steve Chapman of the Chicago Tribune questioned the underlying assumption that installing cameras reduces crime by deterring potential wrong-doers and helping to apprehend those who do commit crimes.

Chicago has installed an estimated 10,000 security cameras and Mayor Richard M. Daley expressed an interest in placing a camera on on every street corner in Chicago.

According to Chapman, a study by the British government, which widely deployed security cameras throughout the country, indicated that the cameras have had “no overall effect on crime”. Chapman also cited University of Southern California researchers who examined two neighborhoods in Los Angeles and “found no visible benefit from this sort of surveillance”.

Contradicting these studies, other researchers have found that cameras can actually help deter crime. The preliminary findings of a study led by Nancy La Vigne, the director of the Justice Policy Center at the Urban Institute in Washington, show that cameras are a cost-effective method to fight crime.

La Vigne and her team studied the effects of cameras deployed in Chicago, Baltimore, and Washington, DC. They found that in some areas the cameras had resulted in “a significant decrease in total monthly crime numbers”, although in other areas, she found that the cameras had “no impact”. In Chicago, La Vigne found that every dollar spent on cameras resulted in $4 of social benefits that include reduced crime, savings to police departments and the legal system, and minimized suffering to victims. La Vigne found that security cameras were even more effective in deterring crime in Baltimore and the social benefits exceeded costs by 50 percent. She attributed this to the fact that in Baltimore cameras monitor the downtown area 24 h a day. However, in nearby Washington, DC, she found that the cameras had no effect on crime [3].