How Do Security Cameras Work at Night?

Jul 31, 2019

Security Camera Night Vision

Light is a crucial element for making a camera work. Without light, the camera can’t see anything. So, how do security cameras work at night?
 

Infrared Technology

infrared light is a type of electromagnetic radiation that is invisible to human eyes
Infrared radiation (IR), or infrared light, is a type of electromagnetic radiation that is invisible to human eyes. It is essentially energy, a heat, that all objects emanate. An infrared camera detects this infrared energy and converts it into an electronic signal, which is processed to produce an image.

An infrared camera also has infrared light-emitting diode (LED) lights positioned on the outside of the camera, around the lens, to act as a spotlight to help illuminate the images you want the camera to capture. The more LEDs the camera has built-in, the further away the camera can see.

It’s imperative to know how far away the LED lights on an infrared camera can illuminate objects if you want to know how far a security camera can see at night. High-quality IR cameras, for example, can illuminate objects up to 150 feet away.

Of course, if you only want your security camera to be able to see objects on your front porch, you won’t need a camera with that far of a field of distance.

Infrared cameras generally record a black and white image to ensure optimal low-light image quality. There are infrared cameras that are advertised as color night vision; however, in order to use the color feature, there must be ambient light in the area, such as a porch or streetlight.
 

External Lighting

Motion detector lights also detect infrared waves from moving objects
Another option to make sure your security cameras work at night is to turn on the lights.
Motion detector lights also detect infrared waves from moving objects. When the motion detector senses an object moving across its field of view, it can electronically turn on the lights, allowing your security camera to see what’s going on.

Motion detector lighting for external use can include floodlights or decorative lighting. Floodlights usually have a field of view of up to 240 degrees and a distance range that can extend up to 70 feet or more. Decorative motion-detector lighting includes lights that come on around areas like decks, patios, stairways, or swimming pools.

There are many security cameras that also work in low-light conditions, frequently called day/night cameras. They have image intensifiers in the camera that increases the intensity of available light. However, unlike an infrared camera, they don’t have infrared LED lights on the cameras to generate additional light, so there must be some ambient light in the area.

Lux Number
In photography, lux is used as a measure of the intensity of light that hits or passes through a surface, as perceived by the human eye.

Security cameras have a lux rating, so the lower the lux number, the lower the amount of light needed to capture an image. Cameras with a lux rating of 0.000 can capture an image with no external light required.
 

Mixed Lighting Conditions

Most security cameras must work in diverse lighting conditions
Most security cameras must work in diverse lighting conditions, protecting a home or office during the day and night. How the security camera adapts to changes in lighting conditions is one of the most important components in choosing a good security camera.

For example, cameras pointed at a front door must deal with changing lighting situations. When the door is opened, sunlight pours in, flooding the camera’s sensor. Without the ability to adapt to this lighting change, the camera will show a bright scene outside the doorway, but the person entering the house will be a dark blur.

High Dynamic Range (HDR) cameras have special light-handling features that handle changes in lighting situations like these.

Need additional help choosing the right security cameras for your home or office? At FSS, we strive to stay on top of industry trends and provide the most reliable security surveillance equipment on the market. Contact us for a free consultation.

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