What are night vision goggles and binoculars?
Night vision goggles and binoculars are electronic devices that allow the wearer to see better in the dark. They are hands-free alternatives to other night vision devices. Although there are some products for general consumers, night vision goggles and binoculars are usually used for military or law enforcement purposes. These devices tend to be very expensive, and the most advanced models may cost thousands of dollars.
Night vision goggles (sometimes called NVGs) usually do not have magnification capabilities, so the image you see is similar in distance to your naked eye. They cover both eyes and provide the wearer with better depth perception than monoculars or cameras. To some extent, they are artificial improvements to your natural night vision ability.
Night vision binoculars, monoculars and cameras are more popular among ordinary consumers. These devices are usually used for low-light security, hunting and wildlife observation. You may even own a night vision device without knowing it.
What types of night vision goggles and binoculars are there?
Generally speaking, there are two types of night vision goggles and binoculars: image intensification and thermal imaging. Each one can let you see things in the dark, but in completely different ways.
Also known as image enhancement, image intensification is what many people think of when they think of night vision. It is the kind that paints everything green. Image intensifiers work like this:
Light, composed of tiny particles called photons, enters the image intensifier.
In low-light conditions, this ambient light usually comes from the moon, stars or light bulbs in the area.
The image intensifier changes the way photons behave by converting them into electrons and then back into new photons.
This process makes the light brighter or enhanced.
Sometimes a green filter is used to make the magnified image easier and more comfortable for your eyes to see.
The upgraded photons enter your eyes, and the original low-light scene looks brighter.
This type of night vision makes low-level light easier to see, but it cannot create something out of nothing. Image intensification cannot work in total darkness.
When a night vision device uses thermal imaging, it converts invisible heat into pictures or colors that we can see.
Our eyes can only see a small part of the electromagnetic spectrum. All light and radiation have a position on the electromagnetic spectrum. The shorter the wavelength, the lower the radiation on the spectrum. The wider the wavelength, the higher the radiation on the spectrum.
Our eyes can only see a small slice of this range. This visible light is everything we see around us. However, thermal imaging allows us to see infrared radiation (IR), which is usually invisible to the naked eye.
Infrared radiation is heat emitted by objects. Thermal imaging devices can detect and measure this heat and convert it into images of different colors. Usually, the warmer the color, the higher the temperature; the colder the color, the lower the temperature.
Therefore, using a thermal imaging device, you can see anything that emits heat in the dark, such as people, animals or vehicles. You can also see some things that do not emit heat but are heated by other objects, such as walls or floors.
What are the advantages and disadvantages of night vision goggles and binoculars?
Night vision goggles and binoculars have many advantages but also some disadvantages. Here are some main aspects:
Improve night vision: Night vision goggles and binoculars can let you see better in the dark, thus improving your safety, efficiency and enjoyment.
Increase depth perception: Night vision goggles and binoculars can let you judge distance and speed better, thus improving your navigation and orientation skills.
Expand activity range: Night vision goggles and binoculars can let you do more activities in the dark, such as observing wildlife, hunting, fishing, camping,hiking etc.
Discover hidden information: Night vision goggles and binoculars can let you discover some information that is invisible to your eyes,such as infrared markers,invisible ink,fingerprints etc.
Increase fun: Night vision goggles and binoculars can let you experience a world different from daytime, thus increasing your fun and excitement.
Expensive price: Night vision goggles and binoculars are usually expensive, especially those using advanced technology,may cost thousands of dollars.
Heavy weight: Night vision goggles and binoculars are usually heavy, especially those using magnification functions,may bring extra burden and fatigue to users.