The RCX Trail Camera System captures images with no moving parts. The XD™ processor silently captures the image from the CMOS sensor as soon as the PIR sensor is activated. The Infrared Filter activates at night, and then deactivates in the morning, providing instant spectral adaptation to protect the highly sensitive sensor from infrared rays during the day. It then responds in spectacular detail at night when the filter moves away from the camera lens. Moving the filter just twice a day conserves battery life and minimizes noise that can alert game to the presence of the camera. Compare this to other camera systems that produce an audible, often game-spooking “clicking” noise each time a picture is taken.