Lux = Used more often than lumens when discussing security cameras, a lux is a unit of illumination. It measures the amount of uniform light that falls on one square meter (expressed in one lumen per square meter). Security camera specs use the lux to indicate how much light they require to operate, with lower lux levels indicating a camera as more effective in lower ambient light. Look for 0.2 lux or less when choosing a low-light camera, and two lux or higher for daylight cameras. Refer to the specification sheet of the individual camera to see its lux rating. Below is a standard Lux Chart for your reference.