An infrared security camera has infrared LED lighting (light from a different region of the electromagnetic spectrum than we normally use to see) installed around the outside of the lens of the camera. This lighting allows the camera to capture a good image in no light at all. With a little bit of light (called low light) the infrared camera can capture a picture that looks just like daytime. People use infrared security cameras for businesses that have the lights out at night (in case of break-ins). Or for outside, nighttime viewing. Keep in mind that even at night time there is a normally some light from the moon, stars, or street lights.
Infrared cameras are often called “Night Vision” cameras because they can ‘see’ at night. However, do not confuse “Night Vision” with “Day / Night Cameras”. Day / Night cameras do not have infrared lights built in. More about those types of cameras below.
Infrared security cameras will provide a color picture while the light is good. When it gets dark, the camera will switch to infrared mode and illuminate it’s built-in infrared LEDs. In infrared mode the image is captured in black and white – this is true of all infrared cameras. The level of light required to capture a good picture is referred to as a camera’s lux, the lower the lux the better the camera can see in low light. For example a camera with 0.003 lux is better than a camera with 0.2 lux. Infrared cameras are considered to be 0.0 lux in infrared mode – in other words they can ‘see’ with no light at all.
If you are going to use an infrared camera outdoors, its best to use a outdoor weatherproof bullet style camera. This is because if you use an indoor infrared camera and need to put it in an outdoor housing, sometimes the infrared light reflects off the glass of the housing. Some people get acceptable results if the camera is absolutely flush up to the glass thereby reducing the glare. An alternative solution is to use a day / night camera which has an extra sensitive imaging chip that allows it to capture a good picture in low light situations without using infrared lighting. This works well for example if there are street lights outside or an exterior light that can be left on at night. Keep in mind that cameras without infrared lighting will not capture an image with zero light.
Another issue to consider is that infrared cameras require more power (more amperage) than non-infrared cameras. The power requirements are provided in the specs for each camera.