There is nothing more frustrating than having a video surveillance system capture footage of an incident, only to find that the images are unusable due them being too dark, too light or having too much glare. When this occurs, the culprits are most often the lighting, the wrong type of camera being deployed or the improper placement of a camera.
Successful deployments must take into account daylight and nocturnal requirements, as well as variances with environmental factors. Camera selection and placement are also critical to thwart vandals and reduce glare, so useful images are not corrupted. All of these factors should be weighed by a campus considering the installation of a video surveillance system.
Lighting Varies Depending on the Campus Environment
The quality of a camera image is contingent upon adequate lighting, but lighting availability and the amount of it required for useable images varies in nearly every environment. For example, a poolside area reflects a great deal of light and has very different requirements from a parking lot or an office area.
The starting point for developing and capturing the best images is an analysis of existing lighting levels. The volume of light itself is measured in a variety of ways but most commonly in lux or foot-candle units. For video, the measurement of composite video signals is measured in IRE units, with 100 IRE units typically producing the best video imaging, while 50 IRE is considered half-strength.
When adding light to an area, LED lights are most preferred for video surveillance systems as they are very reliable and efficient. Alternatively, florescent lights are less favorable because they cause a noticeable flicker in the camera image. If lighting cannot be adjusted or enhanced to accommodate the surveillance system, an integrator can recommend cameras that perform well in low- or no-light situations.
For example, whereas traditional surveillance cameras lose color image quality when the lighting level drops and produce blurred images when motion is present, cameras with elevated sensitivity can enhance the contrast in low-light images, boost color clarity and eliminate “ghosting.” Day-night cameras are suited for around-the-clock security applications because they can work well in any light by using infrared (IR) technology when there are low-light levels.
IR Appropriate for License Plate Image Capture
Infrared illumination is invisible to the human eye. Thus, even though a nighttime scene well-lit by infrared illumination appears dark to human observers, high performance day-night cameras are able to produce excellent images. When infrared illumination is properly applied, the cameras do not need to work as hard to capture usable video, eliminating hotspots and under-exposed shadow areas. These are replaced with evenly-illuminated images from which details are clearly seen.
Although IR has a great number of useful applications, this capability is particularly beneficial when cameras are capturing images of license plates on moving cars, for example, in access and exit areas. If the video is to be used as evidence in legal proceedings, the images need to be crisp and decipherable.
Separate infrared illuminators can also be used in combination with day-night cameras, giving that extra boost and enabling the camera to capture useable images at greater distances. This technology can help take the guesswork out of lighting, as it enables cameras to deliver high-quality images in places where lighting levels fluctuate or in areas where you’re unsure if the lighting is adequate.
Poor Lighting Can Lead to Wasted Bandwidth
Lighting can impact more than just the quality of video. It can have an impact on several areas of your CCTV system. Snowy images or video resulting from inadequate lighting produces larger file sizes that require more bandwidth to transmit across a network and greater storage resources. Grainy images can also be misinterpreted by systems set to record on motion and trigger continuous recording.
By improving video quality through the use of day-night cameras or infrared illuminators, video can be compressed further, resulting in smaller file sizes, lower bandwidth requirements and more efficient use of storage technology.
Quality images also help improve the accuracy of video content analytics (VCA) that will trigger alarms based on behavior patterns, such as a person loitering or an object stolen or left behind. While VCA is just beginning to be more widely adopted due to lower price points, it can help make campus safety personnel more efficient by transmitting to the dispatcher only video that the campus has deemed important through its analytic rules. This enables camera channels to be monitored more effectively and makes it easier to search for events that have already occurred.
Choose Your Camera Location Wisely
In addition to camera selection and lighting, placement is critical. While many cameras offer vandal-resistant housings, it is best to keep cameras up high and out-of-reach. Different types of mounting solutions are available to adapt to individual site requirements.
Installing each camera at a proper angle to reduce glare is critical when capturing usable images. Eliminating glare is difficult when cameras are placed by necessity to view bright exterior entrances, streets where oncoming headlights often shine in the direction of the camera, or sites where there is an interface between bright and dark areas, such as a dark parking lot transitioning to a bright corridor. Through careful positioning, however, the problems with glare can be eliminated or reduced.
Many cameras have embedded features that compensate for these variables to combat distorted images. For example, backlight compensation uses algorithms to help smooth out shadows and highlights to produce clearer images that will show the specific features of an individual instead of a dark figure encased in a bright background light. AutoBlack functionality, found now in both monochromatic and color cameras, brings out details in scenes, such as foggy, dusty or snowy situations where clear video can be difficult to capture.
When placement, camera selection and lighting are all properly accounted for and the appropriate functionalities are deployed, hospital, school or university constituents can rest easier knowing their security cameras are capturing images they can decipher and actually use in a court of law if necessary.
IP Cameras, Convention Domes and High-Speed PTZs Most Popular on Campuses
Overall, three types of cameras are emerging as top choices in campus settings:
- IP cameras, which are being deployed with growing frequency and can include the subset of megapixel cameras
- Conventional dome cameras and fixed mini-domes, which are vandal-resistant and often used in hallways and stairwells
- High-speed, pan-tilt-zoom cameras that can hone in on details with 36x zoom levels
Dome cameras with pan-tilt-zoom capabilities, for example, are a great choice for exterior use, or to provide coverage of large areas, such as parking lots. Many can withstand extreme temperature changes and work well in sunny conditions, as well as in rain and snow.
Alternatively, fixed mini-dome cameras are a natural choice that blend well in interior applications and can be mounted high in a hallway or stairwell, out of reach of vandals.
Low-Light Cameras Keep Close Eye on Franklin & Marshall College
Picturesque by day, the quaint tree-lined streets surrounding Franklin & Marshall College in Lancaster, Pa., became a darkened backdrop to a rash of vandalism in the fall of 2006, prompting the school to intensify efforts to safeguard its community by placing an eye on crime. The student government insisted the best way to enhance safety and security would be through the widespread installation of video surveillance cameras to monitor potential criminal activity.
Part and parcel to the success of the college’s surveillance system was the particular concern involving lighting and camera placement. These and other factors were weighed by the college in collaboration with the adjacent community to address technical requirements while striking a balance with aesthetic concerns.
Franklin & Marshall turned to integrator Tri-M Group based in Kennett Square, Pa., to design and install the new surveillance system. To date, the group has successfully installed 23 Bosch AutoDome modular cameras around the college’s perimeter in predominantly student traffic areas, parking lots, and select off-campus sites to improve visibility and monitoring. Each specific site location was analyzed to best assess its lighting needs, using special cameras for low-light situations when needed.
“We assess each location, and look at what we want to achieve for each site. An interior campus location may have different requirements from the outlying perimeter of the campus,” says Maureen Kelly, director of Franklin & Marshall’s department of public safety. “Parking lots happen to be the easiest to light and install cameras, as they have no blockages and the views can be expanded.”
Since aesthetics was another concern of the college, the cameras were encased in special housings to match the decorative streetlight poles and traffic light arms on which they were mounted. This helped the cameras blend in with the street’s décor.
College Establishes Partnerships With Adjacent Community
But before the installation could get underway, the campus had to develop good working relationships with its surrounding community. Often, as in the case of Franklin & Marshall, vandalism knows no boundary. Any public safety threat in college towns is one shared by both the school and the community. It is up to both to craft a technological solution to protect both students and residents.
Presented with a problem, Franklin & Marshall spearheaded a joint task force with the city and the James Street Improvement District. Their goal was to devise ways to make the city streets surrounding the school “safe and clean” while maintaining the trademark open college campus environment. In addition to addressing camera and lighting issues, they also upgraded municipal lighting, trimmed trees, supplemented their efforts with bike patrol ambassadors, and stepped up police patrols to thwart criminal activities.
To Maria Cimilluca, Franklin & Marshall’s director of facilities and operations, successful security solutions to broad-scale community problems hinge on having strong leadership and direction from the top, as well as having supportive, established working relationships at all levels throughout educational and civic organizations. In the case of the college, Cimilluca said she worked cohesively with internal groups such as the school’s information technology (IT) department, and externally with local utility companies.
“Projects move along faster when you are all working toward the same goal and have a spirit of cooperation,” Cimilluca said. “I hope other schools encountering similar problems will draw from our successful experience and find the technical solutions they need by talking to each other and working together.”
The project was so successful, in fact, that an additional four cameras are slated for installation this summer.
“The priority was to make our school environment and community neighborhoods safe for college students and residents alike,” said Kelly. “This has been an incredibly successful initiative because it has buy-in from people at every level, from the students themselves, to the college president, from the next-door neighbors, to the police department. The new system makes people feel safer.”
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Cheryl Bard is product marketing manager and Willem Ryan is product marketing manager for Bosch Security Systems Inc. For additional information on Bosch, visit www.boschsecurity.us.