Smile--You're On Camera

Many schools and universities are installing closed-circuit television (CCTV) systems for security surveillance. Unfortunately, sometimes these systems are being installed without a clear understanding of what benefits the system will provide, and how the system will be supported by other security measures. Often, people think cameras alone will eliminate security problems.

Even the best designed and installed camera system is nothing more than a security tactic or tool to support the overall school security plan. Typically, cameras do not prevent an event from happening; usually they are used to review the event after the fact in an investigation.

Why cameras?

A solid security plan for a school facility should answer the question, “What are we interested in protecting?” If the answer is personnel and property both inside and outside the building, a school or university needs to identify its trouble spots. Is the institution more likely to have an assault in the parking lot or have equipment carried out the back door?

The configuration of the camera system needs to be based on a philosophy, such as the desire to record the face of everyone entering the building. If you also want to record the face of a person leaving the building, especially those stealing equipment, you will need at least a second camera, since the first will only view the back of the subject's head. If you also want general surveillance of long corridors, the images of persons at the far end of the corridor may be too small to identify, but might be adequate to identify a person carrying equipment.

When trying to protect the exterior building perimeter, parking lots, utility connections and other outside areas, you must use exterior cameras. Exterior cameras are more expensive than interior cameras because of the cabling pathways and weatherproof environmental housings. Exterior cameras also must adjust dynamically to a wide range of lighting, from direct sunlight to little or no light in the evenings.

For instance, a DSP digital camera can balance the light in multiple zones within the image. Monochrome (black and white) cameras can see better in low-light conditions and have sharper contrast. Some color cameras will switch to monochrome automatically when the available light drops.

The use of a pan/tilt/zoom (PTZ) camera is not always an effective way to eliminate the need for multiple cameras. The cost for a PTZ camera is three to five times the cost of a fixed camera, and a typical PTZ camera is not able to view all 360 degrees at the same time. It is possible for a person to see where the camera is aiming and stay out of the line of sight.

PTZ cameras are adjusted by human intervention, or a signal from a motion detector or door contact. Since security personnel are not always available to move the cameras, sometimes events are not seen or recorded. PTZ cameras can be programmed to oscillate like a fan, but again, a vandal can determine where the camera is pointed and avoid the camera's view. In addition this can create a great deal of wear and tear on the camera motors, and increased maintenance costs.