Getting the most from an analog system

Technological improvements are making "old" surveillance systems new again


IP video is the "buzz" of the video surveillance industry, and it certainly does have a number of clear advantages. However, while the future is likely to be networked video, the present is most certainly analog. IP shipments may be growing at a breakneck speed, but they started from a very small number. The vast majority of today's video shipments and installed base is still analog.

Sure, it would be nice if we could jump to the latest technology, but for most of us, that is not possible. We have significant investments in the systems we have. In this environment, we will need to squeeze the most return out of the company's investment. Still, while a wholesale upgrade may not be in the cards, a few tweaks here and there can make a major difference in the value your system delivers.

What those tweaks might be depend on the system you have now, but in any case, replacing boxes - whether they are your cameras, recorders or monitors - involves little expensive labor or installation and can be a very affordable way to improve your system.

Upgrade the Cameras

Let's start with the most critical piece of your analog systems, the cameras. Today's analog cameras offer significant improvements over the cameras you would have installed even two or three years ago.

At the top of the list is likely to be improved resolution. Why so important? The whole point of a surveillance system is to capture events with enough clarity to see what is going on. Whether it is a camera on a front door that needs to capture clear images of faces, a camera over a point of sale that needs to see the denominations of bills going into the cash drawer, or a parking lot camera that needs to pick up license plates - if your camera starts out with a fuzzy image, there is nothing the rest of the system can do to improve it. Today's cameras can provide as much as 600 lines of resolution, where as five years ago, 480 lines was state-of-the-art.

Another area that has improved in contemporary cameras is light sensitivity. Today's cameras not only have better sensor technology, but also have improved features such as "sense up" (an automatic increase of exposure time under low-light conditions) to provide dramatically better low-light performance. A lower-cost version of the traditional true day/night - which most manufacturers call electronic day/night - offers better performance than your older cameras (although still not as good as true day/night) for a fraction of the cost. If you are trying to view or capture scenes after dark, indoors or out, replacing old cameras will likely make a dramatic improvement.

Noise reduction is another feature that has changed radically since you bought your last analog camera. First-generation noise-reduction systems filtered noise by averaging the pixels on a single frame, which helps reduce noise in a low-light image, but also reduces the sharpness of the video. Second-generation reduction algorithms averaged pixels between frames, which does a nice job of reducing noise but introduces a blur on any item in motion. Today's best cameras combine the two techniques in a clever way to achieve maximum noise reduction while minimizing the blur. The result is not only a much clearer low-light image, but also the lack of noise prevents DVRs from filling their hard disks prematurely because noise fools their compression by looking like a lot of motion. That's a fix with multiple benefits.

The Dynamic Range of a camera defines its ability to view both very bright and very dark objects at the same time. The need is best illustrated by the camera used in an office lobby - lots of bright windows and an entrance door with frequent pedestrian traffic. A camera purchased five years ago will not be able to see the details of the faces of people in the lobby while picking up the outside details through the windows or the faces of a visitor entering through the bright doorway. The latest Wide Dynamic Range cameras, on the other hand, capture clear images of the people inside and out.

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