Warning: prey in the animal kingdom should beware of things that go “bump” in the night! While other animals are catching some shut-eye, nocturnal predators are on the prowl. For them, a midnight snack is actually a full-course meal. Nocturnal animals include foxes, rats, raccoons, toads, tigers, and vinegaroons (scorpion). Like surveillance cameras that can film at nighttime, night vision is vital for these creatures to function successfully after the sun sets.



By understanding how night vision works in nocturnal animals' eyes, can give us some insight about the functioning of security cameras with night vision. An animal's night vision is based on differences in their eye's structure.

The eyes have it

Nocturnal animals' usually have pupils that open more widely in dim light. Pupils are the small, round, black holes in the middle of your eyes. The result is that nocturnal animals' eyes collect more light than our eyes do. Also, some animals have slit pupils, which are more effective in closing quickly and totally.

Also, nocturnal animals' eyes have specialized rods, which function in dim light. In fact, some nocturnal animals' eyes (i.e. snakes, lizards, bats) have rods, but no cones!

Finally, particular nocturnal animals have a “tapetum,” which reflects back into the retina, for a second time. This is what makes cats' eyes seem to glow in the dark!

Since security cameras have no pupils, rods, or tepetum, how exactly can they “see” at nighttime? In the world of electronics, basically two methods are used:

The heat is on

Through thermal imaging, the top portion of the infrared light spectrum is collected. This energy is actually given off as heat, rather than being reflected as light. Objects that are warmer, such as people and animals, give off more heat than objects, such as buildings or vehicles.

Improving your image

On the other hand, image enhancement involves taking in very small amounts of light. That includes the lower half of the infrared light spectrum. This light exists at nighttime, but our eyes may be unable to perceive it. The light is then intensified until we can observe whatever images the surveillance cameras are capturing.

Make night vision the right vision

When installing night vision security cameras, here are some guidelines to make them more effective:

Exterior building entrances. Placing night-vision security cameras at exterior building entrances, can serve a variety of purposes. Monitoring who enters and exits a building can reduce intruders and employee theft.

Rural perimeters. Rural areas tend to be more difficult to secure, based on the fact that fewer people are typically responsible for securing a larger area. A security camera can make it easier to monitor a rural perimeter.

Sleeping infant. An infant must be monitored at all times, even when you cannot see him or her sleeping at night. Night vision security cameras allow you to keep and eye on your child, during all hours of the night.

Although we humans are programmed to sleep at night, rather than during the day, surveillance cameras can keep an eye on our possessions and loved ones, from sunset to sunrise. It is the next best thing to cat eyes!