It is highly likely that many of us purchased or specified our last analog camera in 2006. Ongoing and upcoming projects will probably focus on Internet protocol (IP)-based cameras. Relying solely on the now ubiquitous IP network infrastructure, this class of devices has revolutionized how we use technology to meet our surveillance requirements.
If you're looking at new IP cameras for a security implementation, you and your specifier have a lot of options. Different IP cameras offer different features and capabilities that may or may not be ideal for your project.
In some ways, selecting an IP camera isn't that different from selecting an analog camera. One of the still-present constraints on any surveillance system is lighting. Both IP and analog video systems require appropriate lighting for effective operation.
Specification sheets for many of today's IP cameras show a continual decrease in the amount of faceplate illumination required for useable video. You'll commonly see minimum illumination levels of less than 0.5 lux for color and 0.1 lux for black and white in camera specifications. These numbers are usually qualified with a very low f-stop number, allowing the maximum light in through the lens iris. They are normally further qualified by indicating that the automatic gain control (AGC) is on. In other words, the video at these light levels could be defined as usable, but only barely so.
Don't view published minimum illumination levels as operational recommendations. Your installation location should provide lighting at levels at least a factor of ten above the published minimums. Additionally, it is always appropriate to have the vendor or integrator bring the specified camera to the site in order to actually observe the produced video signal under existing lighting conditions. This allows changes in either the camera selection or lighting conditions before full-scale implementation.
Power Over Ethernet
Of course, another practical requirement IP cameras share with analog is power. But IP cameras have more power options than analog cameras have had. With the approval in June 2003 of IEEE standard 802.3af, power can be delivered to IP-based devices over the Ethernet network cable.
Power over Ethernet (PoE) has greatly streamlined IP camera system design and new installations by providing data transmission and power supply in one cable from a common source. This can offer an installation great benefits, since both the data and power now come from and are maintained by the IT department. As a secondary benefit, backup (uninterruptible) power now also comes from a common source. Many companies offer rack-mounted devices that provide power, power monitoring with alarm notification, and UPS power, all in one box.
Use of POE features requires that the network connection to the IP camera come from a POE-enabled switch or router. For legacy network hardware, POE-enabled devices are approximately 20% more expensive than non-POE devices. For a 24 port switch recently reviewed for a project, this differential represented around $1,000. However, new-generation POE-enabled switches and routers are often approximately 20% less expensive than non-POE devices.
When your design firm is analyzing the cost benefit of POE for IP cameras, they'll need to keep in mind the type of network devices to be used. Since POE-enabled network devices normally come with ports in multiples of 24, any upcharge for the POE function is minimal on a per-port basis. For example, an upcharge of $1,000 represents approximately $42 per port. This is much less than a typical charge to run a new power drop to a CCTV camera. Conversely, even if power is available at the camera location, use of POE would add a minimal amount to the installation costs while at the same time eliminating legacy, low-voltage power supply hardware.