CCTV cameras with PIR motion sensors

PIR sensor

— infrared sensor that responds not just to movement in the frame, but to changes in thermal radiation from a human, animal, or other warm object. Unlike regular software-based motion detection, PIR is less responsive to shadows, rain, snow, swaying branches, and other visual interferences. Because of this, a camera with a PIR sensor often provides more accurate alert notifications and bothers the user less with false alarms. However, such a sensor has a limited range and angle of operation, so it's important to aim it correctly. For example, a PIR sensor is especially useful in outdoor cameras at entrances, gates, garages, or terraces.