About Surveillance Camera Technical Features
Lux rating is the measurement used to indicate how sensitive a camera is to light, and stands for the level of light reflected off a piece of paper by a candle from one meter away. Thus a sensitivity of three Lux would mean a camera could generate an acceptable picture of a piece-of-paper-sized object that was illuminated by the equivalent of three candles from one meter away. The lower the Lux level, the better the camera's ability to work in low-light conditions. The camera's resolution should be greater than or equal to the resolution supported by the system's recorder or monitor. The S/N, or signal to noise ratio, is an important measure of a camera's quality. A poor camera, low-light conditions or poor wiring causes "noise" which consumes processing power and disk space. A camera with a wide dynamic range is ideal, especially for recording areas in which both indoor and outdoor light are present. CCD (charge-coupled device) sensors provide high-quality images that are less susceptible to noise. CMOS (complimentary metal-oxide semiconductor) sensors offer less image quality, but are usually more cost-effective and energy efficient.