When most of us think of night vision devices we usually picture the elaborate electronic headgear or special cameras used by military personnel. We usually assume the technology is complicated and the price exorbitant and so we also assume that attractive as being able to see in the dark may be, it’s beyond the realm of us mere mortals. This is somewhat humorous however because those in the know already realize that not only is night vision technology affordable and readily available, it is quite common and many people already have it in their possession. Before we can go into the specifics, let’s take a moment to make a few observations of the obvious.
Since cameras were first invented the public has held a longstanding fascination with the ability to capture images. Photographic technology rapidly advanced from its early beginnings to the point where anyone could simply walk into a store and for a tiny sum be able to take pictures anytime and anywhere. This also included the ability to capture full motion films as well and before long, miles of film were being exposed everyday all over the world. Up until the last twenty five years, however, film was the only medium images could be easily stored on. This changed with the introduction of video tape and thus photography and filming began moving into the age of solid state electronics.
With the advent of the charge-coupled device or CCD, the digital camera and camcorder quickly made film obsolete for all but the entertainment industry. CCD’s changed everything because instead of using light to cause a chemical reaction on specially prepared film, light is instead converted into an electronic voltage or signal which is then stored in electronic memory. It didn’t take long before the advantages of no longer needing film to capture images were realized. Nowadays, digital cameras and camcorders are as commonplace as the simpler film based devices of yesterday and you could probably find a CCD based camera in just about any household in the U.S.
Most people already understand the difference between today’s cameras and those of yesteryear and know that film is no longer required to capture and store images. Most people also understand that all forms of photography are basically nothing more than a way to capture light and in turn impressions of the objects it illuminates, more commonly known as photographs. What most people don’t know, however, is that CCD’s have another trait that sets them apart from the film based cameras that preceded them. With the exception of specially prepared films, most film based cameras are sensitive to the same light spectrum as the human eye. When there is no light, you cannot capture an image. CCD based devices however are almost all sensitive to a larger swath of the light spectrum. As well as being able to capture the visible light spectrum, CCD based devices like camcorders and modern video cameras are also sensitive to the infrared, or invisible light spectrum. What this means, is that with most camcorders or video cameras, all you need to do to take pictures in the dark is provide a source of infrared light.
Infrared light is no different from visible light. It behaves the same way, only it radiates at a frequency that is undetectable to the human eye. CCD devices, however, can detect this wavelength and thus form images from infrared illumination. In fact, some camera manufacturers have already exploited this natural characteristic of CCD’s and introduced versions of their devices that are touted as low light or night vision capable, yet in reality differ little from their normal offerings only by having a source of infrared light included with the camera. True some devices now use CCD’s that are specially designed to increase their sensitivity to light in the infrared spectrum, it still remains though that almost all CCD’s are capable of capturing images in what for all practical purposes amounts to total darkness using infrared.
As can now probably be understood, just about anyone with a camcorder or digital camera can “see” in the dark using night vision. The only real trick is to add a source of infrared light. Many of the cameras sold as having night vision capability are little more than a camcorder with a couple small LEDs added that emit infrared light. While they work, the results are usually less than impressive. Their range is poor, and the low power of the LEDs causes the camera to produce images that are low in resolution. To get the full ability of a CCD camera, a strong infrared light source is necessary. Consider infrared light the same way you would visible light produced by a flashlight. A tiny penlight is going to produce only a little light, and will not be much good for illuminating a large area or brightly illuminating a room. A full sized four cell flashlight on the other hand produces a lot more and brighter light, thus you can see more. The same is true with infrared light and cameras. If you have only a little infrared light, the images will be poor and hard to see, if you have a lot of infrared light the images will be clearer and easier to view.
The principle here is not just applicable to camcorders and personal cameras. If a device uses a CCD, it is likely sensitive to light in the infrared spectrum. This means that home security cameras, commercial security systems, trail cameras used for hunting and the like may all benefit from the addition of an infrared light source. It is fairly easy to test whether or not a camera is IR sensitive by simply pointing it at a source of infrared light like a television remote and seeing if the infrared light emitted by the remote is visible on the devices’ display. If it is, you can likely use infrared light with your device.
Providing a source of infrared light is as simple as finding a powerful infrared emitter like a Larson Electronics LEDLB-24-IR LED IR Emitter Light and setting it up to illuminate the area you want to cover. Keep in mind, just like with visible light, the more infrared light you can place on the area in question, the more easily your cameras will be able to see it. You also of course have to avoid things like placing the infrared light source where it can shine directly at the camera which will produce blinding effects just like with visible light. Most cameras not designed specifically for use with infrared are sensitive to IR in the lower ranges, so look for infrared lights in the 700nm to 850nm range. With a little testing and experimentation however, just about anyone can turn their personal camcorders or home security cameras into night vision capable devices by doing little more than adding an infrared light source.