What does LUX rating mean in CCTV?

CCTV Camera Pros very often gets the question from our customers "What does LUX rating mean?"

Here is an explanation that was written by Chris a while ago that I just came across:

In the world of CCTV and security cameras the term LUX is used to describe how well a camera can capture video on low light. The amount of light is defined by LUX (lumens per square meter). One LUX is the amount of light cast by one candle at one meters space. Here are some examples of common light sources expressed in LUX.

LUX Rating Chart

• Full sunshine 10,000 LUX
• Well- lit office 500 LUX
• Comfortable reading 300 LUX
• Cloudy 100 LUX
• Twilight 10 LUX
• Dusk 1 LUX
• Full moon .1 LUX
• Quarter moon .01 LUX
• Complete darkness 0 LUX

Some high quality Sony CCDs can have a good picture down to .1 LUX. Anything lower and they will require infra-red LED's to see in the dark. These are called night vision or IR (infrared) cameras. Most camera specs will list the number of LED's (which people tend to use to compare low light performance). In actuality, the type of LED is more important than the quantity of LED's. Some LED's produce 10 times more light than others. Still others are made so the naked eye cannot see the light being emitted from them, making these better for covert use. Comparing the amount of feet the camera illuminates and how wide the light spreads is the best method to compare IR cameras.