How do Night Vision Goggles work?
Night vision goggles come in handy for hunting, home security, wildlife monitoring, military, and law enforcement. How night vision goggles work depends on the specific goggle you are using. There are two types of technology used in night vision goggles; image enhancement and thermal imaging.
Types of Night Vision Technologies for Goggles
Image enhancement- is what many people picture when they think of night vision and is one where everything is coated in green color. It amplifies existing light making images easier to see. Tiny bits of light called photons enter the image-enhancing goggles. This ambient light is usually gathered from the moon, stars, or light bulbs in low light conditions. The goggles change the way the light photons behave by converting them into electrons then back into new photons. The green color is sometimes used to make the amplified image easier for the eyes to see. The upgraded photons enter your eyes and the formerly low light scene appears brighter. Using image enhancement technology, night vision googles collect all the available light. They then amplify it so that you can easily see what is going on in the dark.
Thermal imaging –this technology is related to heat. Hot/warm objects including human bodies give off some heat in the form of infrared heat. These devices use thermal imaging technology to capture that infrared light. You are thus able to see an image of what is happening in the dark. Thermal imaging gives us a peek at infrared radiation which is usually invisible to the unaided eye. Infrared radiation is associated with heat and objects containing more heat tend to produce more infrared radiation. It is based on the amount of heat being emitted by objects. Additionally, this technology functions well when trying to see people in the dark. It is also ideal for the darkest conditions.
Night Vision Goggles Uses
- Hunting
- Military and law enforcement
- In the farm
- Home security
- Wildlife watching
- Intruder prevention.
How do Night Vision Goggles work?
However, most night vision goggles use image enhancement technology.
Here is a detailed process of how night vision goggles work:
- Dim light from a night scene enters the front lens. The lens is made of photons of all colors
- As the photons enter the googles, they strike the photocathode which is a light-sensitive surface that is a bit like a solar panel that is very precise. Its function is to convert photons into electrons.
- The electrons are amplified by a photomultiplier which is a kind of photoelectric cell. Each electron entering the photomultiplier causes more electrons to leave it.
- The electrons leaving the photomultiplier hit a phosphor screen that is akin to an old-fashioned television screen. The electrons create tiny flashes of light as they hit the phosphor.
- The screen makes a much brighter version of the original scene as there are more photons than the ones that originally entered the Goggle.
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