“Night vision” generally refers to cameras that make use of infrared (IR) light to see in low or complete darkness. The quantity of light available is measured in “LUX”. which is defined as “lumen per square meter”. Street lighting provides approximately 1 to 10 Lux. A full moon provides approximately 0.1 Lux. There are many cameras that can capture a quality image with as little as 0.03 lux without the aid of infrared emitters, those little LEDs (Light Emitting Diodes) that look red or blue in color when powered (see illustration).
Regardless of the type, images in low light are only possible in black and white – not color. Mobotix offers a camera that include a color *and* a black and white lens. The camera automatically switches to the black and white lens when needed.
IR emitters can be added to provide additional light to help black and white security cameras capture a better image. Manufacturers of IR assisted night vision cameras will often provide an estimated distance of how far the camera can see in the dark. If night shots are what you need, be conservative with IR range estimates to be on the safe side. For black and white cameras that do not have built in emitters, standalone IR emitters can be added to your environment to help obtain the image you need and are often preferred as they can keep bugs away from the camera.
Below is an image capture from a Mobotix camera which allows for the current Lux rating to be displayed on the screen.