When building a surveillance system, it is important to select cameras that meet the needs of your organization and installation. This includes selecting specific types of cameras to meet the locations where cameras are needed and the intricacies of the venue, including fixed, pan/tilt/zoom (PTZ), vandal-proof, or fixed-dome cameras.
There are all types of network cameras available today, and no matter what your needs are, a network camera is available to meet them. Although analog cameras are available in a similar variety, network cameras are now offering added benefits, including better image quality and more installation flexibility. And for some special applications, such as very high-resolution needs, or wireless, network cameras are the only option.
Selecting the right network camera is a critical for the success of your surveillance system. For example, retail environments will have different needs than schools or highway systems, and every installation has some features that are more important than others. Some may value off-site recording and storage over other features such as Power over Ethernet (PoE) or alarm management.
Off-site recording was particularly important to Todd Jacobson, the owner of a Citgo Sooper Stop in North Dakota. Within three weeks of installing a network video system, his convenience store was robbed. However, because the video was stored offsite, the thief was unable to steal the video tape during the robbery, as is common with traditional analog CCTV systems. Because of the high image quality and the offsite recording, police were able to identify and apprehend the perpetrator within four hours and Jacobson recovered all of the losses from the robbery.
This example also indicates that not all network cameras are created equal. If Jacobson had been using a low-end network camera, it is possible that image quality wouldn't have been good enough to help the police identify the thief. There are many components that go into creating a quality network camera, and security professionals need to understand how these components affect the camera's performance and durability.
Image quality: Image quality is the most important feature of any camera. This is particularly so in surveillance and monitoring applications, where lives and property may be at stake. Superior image quality enables users to more closely follow details and changes in images, making for better and faster decisions. It also ensures greater accuracy for automated analysis and alarm tools, such as object recognition.
When assessing image quality be sure to research the following factors: light sensitivity, the crispness of moving objects, and the clarity level. A camera's datasheet will tell part of the story, but it is a good idea to field test a few cameras before making a decision. In addition, there are some simple steps you can take to ensure high quality images - use enough light, avoid backlight and reduce contrast whenever possible.
It is also critical to take into account the location of the cameras, especially if the cameras will be used outdoors. An auto iris lens, which automatically adjusts the amount of light that reaches the image sensor, should always be used for outdoor applications. Direct sunlight should always be avoided. Mount the camera high above the ground to avoid a contrast effect from the sky. If the camera is mounted behind glass, the lens must be placed close to the glass to avoid reflections. If the camera will be used at night, an infrared (IR) camera should be used generate high quality images in very low light conditions.
Power over Ethernet (PoE): In most buildings today, TCP/IP infrastructure is available by means of Cat 5 and 6 cabling. The cabling can be used for fast transport of data, and the distribution of power to devices connected to the network, using PoE technology. PoE reduces installation costs by eliminating the need for power outlets at the camera locations and enables easier application of uninterruptible power supplies (UPS) to ensure continual operation, even during a power outage.