I don’t know whether you use a pair of night vision binoculars, a question arises in many peoples minds is how night vision devices work? Night vision goggles or cameras are high-end technology allowing you to see something in dark. In this article, we will discuss how night vision devices work, thermal imaging, and its uses. We hope people who have much interest in science and technology will love reading this article.
Night Vision optics
Let’s start our discussion with night vision devices. How do these devices work? Go back to our basic physics. Can you remember what you taught in your physics class perhaps in your high school year regarding why we see something? Your physics class teacher taught you that light is composed of particles. When these particles fall on something and bounces back to our eye’s retina, we see something. Well, it’s maybe the most simplistic explanation of light and the human eye. You may have many other questions like what sort of light particles are, how to the image is created in the retina, or what is the role of our brain in the entire image creation process. But, those are lengthy discussions. We don’t like to move into a detailed discussion.
We want to convey the message to you that the basic principle of image creation whether it is with a camera or your eyes is basically the same. But, what about those night vision binoculars? Not only night vision binoculars. There are other types of night vision devices like monocular, goggles, and cameras as well are available in the market. Thanks to the advent of NVD’s particularly, night binocular, greatly facilitate many activities at night which include hunting, nature viewing, hiking camping, and fishing. Night vision binoculars of many high-end brands are also quite available in the market.
We reckon these night vision devices are a scientific wonder. It is because, in optics, presence of light is essential to see something. But, these devices don’t need visible light? So, how do they function? The answer lies in physics. Now we needed to move to a little advanced level of physics.
Different objects we encounter in our everyday life emit thermal energy. Even ice could emit energy. The equation related to object and emitted radiation is quite straightforward. The hotter an object the more heat it will radiate. Another thing is that not all objects emit the same intensity of energy. Two objects placed side by side will emit thermal energy with different intensities. It means there is a difference between the emitted thermal energies of two different objects. Night vision devices or FLIR’s can detect the temperature difference between the two objects.
They translate the difference into a detailed image. These devices are so sensitive. They can detect the slightest temperature. The thermal energy that comes off an object is called a heat signature. In this regard, all warm-blooded animals have a heat signature. In simple words, night vision devices use a heat signature to create an image. This is why you see a deer at night with night vision optics at night. But, it’s harder to see a snake at dark with night vision devices. It is because snakes are cold-blooded animals means they can adjust their body temperature with the surroundings. So, these devices cannot differentiate the temperature difference between snakes and surrounding objects and are unable to produce any thermogram.
It may sound completely irrelevant to this discussion, but, we would like to inform you that thermal clothing and thermal imaging are completely different though both of the terms sound similar. Thermal clothing is one type of long underwear. The clothing is ideal for winter when the temperature drops to freezing cold. It’s extremely useful clothing to wear under your hunting jacket. However, there is a remote similarity between thermal clothing and night vision devices. And, that similarity is night vision devices are quite useful for night time outside outdoor activities, thermal clothing is indispensable clothing when it comes to enjoying an outdoor activity like skiing on ice. In this regard, don’t confuse thermal clothing vs base layer. Depending on the situation, they may differ with each other.
Thermal Imaging cameras
These devices are sensors rather than cameras. They can detect infrared radiation or thermal heat that is not visible with eyes. You can say that thermal imaging cameras are one type of radiation detector. The temperature of an object is represented in different colors. A white and black image of a thermogram or thermal image means it’s a hot object.
Various uses of thermal imaging:
Since thermal imaging requires the presence of no visible light, thermogram technology has quite useful in several areas. These are described shortly below. However, don’t mix thermal imaging with thermal underwear. They are completely two different things.
You know firefighters needed to work risking their lives when a disaster strikes. They often work in dark or in an area of dust that makes visibility so poor. Can you remember how firefighters work in a horrendous situation after the twin tower attack in New York on 9/11? In those dire situations, thermal imaging helps saving many peoples valuable life,
Night vision optics are a blessing to night time hunters. Thermal imaging is quite useful to wild hog hunters. Hogs are quite destructive to farm crops. They are also very clever as they usually go after the sunset. They can also hide their presence in bushes. In this regard, thermal imaging helps to detect and hunt these savage animals. Hunters also use thermograms to detect hidden deer.
Police and military
Military and police are common users of thermal imaging. Soldiers and police officers are using thermal imaging rifle scope during conducting a raid at dark.