Infrared (IR) technology in surveillance refers to the use of infrared light to enable video capture in low-light or complete darkness. This technology allows security cameras to operate 24/7, even in conditions where the human eye or standard cameras cannot function effectively.
IR surveillance systems use infrared LEDs to emit light that is invisible to the naked eye but detectable by the cameraās image sensor. This invisible illumination enables the system to record clear black-and-white footage at night without alerting intruders or disrupting the environment.
Types of IR Technology in Surveillance
There are two primary types of IR systems used in security technology:
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Active IR Systems
These systems use a dedicated infrared light source, usually in the form of IR LEDs, to actively illuminate the area being monitored. Cameras then pick up the reflected infrared light to form an image. This is the most common method used in night vision cameras. -
Passive IR (PIR) Systems
Passive infrared systems do not emit any light. Instead, they detect heat or thermal energy emitted by people, animals, or vehicles. PIR is often used in motion sensors to trigger alarms or activate lights when movement is detected.
IR Cut Filters and Day/Night Functionality
Many modern IR-enabled cameras come equipped with IR cut filters:
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During the day, the filter blocks infrared light to ensure color accuracy.
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At night, the filter is removed so the sensor can capture infrared light and produce clear monochrome images.