How Do Night Vision Goggles Work?
If you want to see through night vision goggles in the dark, there are a couple of ways you can go about it. The first way requires a type of technology called image enhancement. This basically means that equipment takes what is there and makes the most of it.
Even in the darkest of conditions, there are tiny bits of light present. Some of this light may be infrared light that isn’t visible to the naked eye. Night vision goggles using image enhancement technology collect all the available light, including infrared light, and amplify it so that you can easily see what’s going on in the dark.
The other way uses a technology called thermal imaging. If you’re familiar with the word “thermal,” you know that this technology has to do with heat.
Hot objects, including human bodies, emit some heat in the form of infrared light. Night vision goggles using thermal imaging technology capture the infrared light being emitted as heat by objects in the field of view. In this way, you can see an image of what’s going on in the dark based upon the amount of heat being generated by various objects.
Thermal imaging works well when trying to detect people in the dark. It’s also better suited for conditions approaching absolute darkness. Most night vision equipment, however, uses image enhancement technology.
Night vision technology has many uses for the military and law enforcement agencies. For example, it can be used to find people in the dark, as well as for navigation and surveillance. Night vision can also be used for hunting and watching animals after dark.
If you’ve ever seen a night vision image, you’ve probably noticed that it always has a green glow. That’s intentional. When available light is captured and amplified, it’s turned into electronic information that has to be transmitted to the eyes.
In essence, this electronic information is colorless. Why aren’t the pictures black and white then? Night vision goggles are made with screens that produce green pictures, because human eyes are more sensitive to green light and it’s easier to look at green pictures for long periods of time than it is to look at black and white pictures.