Challenges in Choosing Surveillance CamerasBy John Honovich, Published on May 10, 2009
With hundreds of manufacturers to choose from and little comparative information available, choosing the 'right' surveillance camera can be difficult. Worse yet, specifications provided by manufacturers are often unhelpful or misleading.
In the camera testing I am now performing, here are four fundamental challenges that continue to arise:
- How well does the camera work in low light
- How well does the camera work in bright sunlight
- How much detail does the camera provide
- How hard is it to configure the camera for optimal image quality
Dealing with Bright Sunlight
While darkness and sunlight may be opposites, they pose equally difficult challenges for surveillance applications. The problems with sunlight are not limited to outdoors. Anytime you have windows or doors that open to the outside (obviously very common), you are at risk to issues with bright sunlight ruining your surveillance video.
The category of cameras that are designed to address is are Wide Dynamic Range or WDR cameras. However, good luck comparing the specifications of various WDR cameras. Often cameras labeled WDR have no technical specifications and those that do usually measure the range in dBs. However, it's not clear how much better an image is created with a 100 dB range than a 60 dB range. Also, manufacturers may measure this differently.
Capturing details of a scene are at the core of conducting surveillance. This is critical in determining if your camera meets its security objective and it's also increasingly important for reducing camera count (by using megapixel).
The stated resolution of a camera is the obvious primary indicator (e.g., Standard Resolution, 1.3MP, 2MP, etc.). However, this is better viewed as the pixel 'potential' than the definite resolution you will obtain.
First, lighting can dramatically reduce the actual details that your camera can produce. To the extent that you have issues with sunlight or darkness (which are very common), your camera will provide details far less than its stated resolution.
Secondly, and this is a special concern for megapixel cameras, not all megapixel cameras, even rated for the same pixel count will deliver the same level of detail.
Determining How Hard Configuration Is
When you see cameras at trade shows or from manufacturer supplied videos, they almost always look outstanding. This happens because:
- Manufacturers have technical experts who know all the configuration options of a camera and have significant experience experimenting with various combinations of settings.
- Manufacturers know what lighting conditions work best with their cameras and are careful to set up cameras to avoid known areas that expose flaws