Did you know that night vision was first used in World War II and came into high use during the Vietnam War?
What is Night Vision?
There are many types of night vision products on the market. Let’s start by defining the difference between Night Glasses and Night Vision Devices (NVD).
Night Vision Glasses are optical devices that allow the operator to have the ability to see images in different levels of light approaching complete darkness. Night Glasses only intensify what light there is already available with purely optical means using large diameter objective lenses only. The most common types of Night Vision Glasses include Night Binoculars (Giant Binoculars that have very large objective lens diameters) and Telescopes that are most likely used for astronomical purposes.
Night Vision Devices (NVDs) are different to Night Glasses because they are not purely optical devices. They are electro-optical devices that comprise of an IR image intensifier tube enclosed in a protective casing. NVD’s amplify whatever existing light there is and send it onto your eyes. You actually don’t look directly through the optics of an NVD as you do with night glasses, you instead look at an amplified electronic image on a phosphor screen. Commonly, NVDs include IR illuminators and telescopic lenses. Examples of these types of NVDs include monoculars, binoculars, rifle scopes, or goggles. Night Vision Devices are commonly used for nocturnal wildlife observation, night vision filming and photography, and marine navigation and security.
How Does Night Vision Work?
The whole process of how Night Vision works is complex and many factors dictate the final outcome. To put it simply, night vision takes small electrical charges not detectable to the human senses and multiplies them to a perceptible level.
Night vision devices such as Night Vision Scopes collect minute particles of light and focus them into an image intensifier. Then the image intensifier converts the particles of light to electrons. Next, the electrons are multiplied and projected onto a green phosphorescent screen. When the multiplied electrons strike the phosphor screen, it causes the screen to emit light that is visible to the naked eye.