How reliable are cameras and video motion detection systems for identifying unwanted intrusions?
Video motion detection systems are not 100% reliable in outdoor uncontrolled environments. Low light can cause the system to miss an intruder, excessive movement from clouds & shadows, headlights from vehicles, dust devils, etc may cause false alarms. Excessive false alarms creates a situation where people lose trust in the system and may ignore a real intrusion.
If you require that your electronic security system deliver mission critical type protection, it’s usually best to use 2 technologies in tandem to detect and confirm intrusions:
PIR, fence or microwave technologies are usually more reliable than video motion detection. These systems are typically used as a primary intrusion detection system, with video being used to confirm alarms
Video motion detection is useful for many situations
Cameras require light in order to deliver useful images
Low light is the enemy of cameras. Low light causes “noise” on images.
More pixels does not necessarily equal better image quality
Under low light conditions, a 12mp image sensor does not gather light as well as a 2mp image sensor. The reason is, more pixels on an image sensor (12 million pixels vs 2 million pixels) means the physical size of the pixels are much smaller, smaller pixels have less ability to gather light. Just like SLR camera lenses…a bigger lens and aperture gathers more light than a smaller lens and aperture.