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. About Dome Cameras
A dome camera is one of the most common indoor security camera styles. Mounted on the ceiling, and often designed to be tamper resistant, dome cameras are designed to be visually appealing and more secure than other types of security cameras. A true dome camera enables a continuous 360-degree pan and 90-degree tilt operation, providing for extensive room coverage. One disadvantage of dome cameras is that they usually are not suitable for low-light conditions and must be used in well-lit areas.