If things are going bump in the night, there's no reason you can't watch them. Even though CCTV cameras need light to pick up images and can't get a clear picture in the dark, that's not a problem if you have an infrared illuminator. By flooding the area with invisible infrared light, IR illuminators let you keep an eye on intruders who mistakenly think nighttime is the right time to break in.
How Do Infrared Illuminators Work?
An IR-illuminator is a device that emits infrared light-low frequency electromagnetic radiation that's outside the visible spectrum. In other words, it gives off light that a camera can pick up and use, but that a person can't see-so while it's still dark to the human eye, the camera can see just fine.
IR Illuminators and CCTV
IR illuminators are especially useful for CCTV systems, which use surveillance cameras to monitor banks, shopping malls, government facilities-even private homes. Since security breaches are likely to happen after hours, it pays to be able to see these facilities clearly in the dark. Of course, if you want IR-illumination to work, you have to use the right cameras. Black-and-white surveillance cameras are the most IR-sensitive; most color-cameras are equipped with filters that block out infrared light to enhance image quality. Many manufacturers have come out with IR-sensitive dual-mode cameras, which offer color images and can switch from daytime to night vision automatically, but the IR-sensitivity of these, too, varies according to the camera. So if you're investing in a CCTV system and want to incorporate IR illumination, make sure you check the cameras for IR-sensitivity in advance.
Types of IR Illuminators
There are three main types of IR illuminators: diodes, lamps, and lasers. Diodes are small, inexpensive, and good for short-range illumination. They also require relatively little power to operate. Infrared lamps are more expensive to buy and maintain, but they can operate at greater distances and are often better for facial identification. Lasers are excellent for long-range image clarity, even in inclement weather, but they're big, expensive, and potentially harmful to the eye if not handled correctly-which is why they're usually only reserved for military use.
The cost of IR illuminators varies widely, depending on what type you buy and where you buy it-anywhere from under $30 on Ebay to around $200 commercially. There is, of course, middle ground, so do your research and shop around. You want to make sure you're getting the most for your money-so not only will you sleep better at night, you'll see better at night, too.