Why Night Vision is Green

0
49

Introduction

If you’ve ever used any device that utilizes the benefits of night vision technology or you’ve ever watched any film in which the NV technology was used to assist people see while in darkness, you’ve possibly noticed that images shown through those devices is ever green. As a matter, when someone mentions night vision goggles, you instantly start picturing a green image. The ability to see what our eyes cannot see in darkness are astounding. The NV technology can be used in civilian operations and military applications. For instance, it can be used to locate survivors after occurrence of a natural disaster or pinpoint the enemy’s location. So why is the color of these night vision images green? This is specifically what we’ll look at in this article. Alternatively, you can find that information at www.agmglobalvision.com. 

Night vision invention

The 1st generation of NV devices was established around 1930s by US and German military and was utilized by infantry and tanks during the World War 2. These NV devices required large supply of power that would be carried by the soldiers. The devices worked on the technology of image intensification. NV devices was utilized for the first time by the United States military during the Vietnam war.  It’s during this war that the concept of making NV technology portable occurred on a practical level.

With technological advancements in the following decades, NV devices became even more sophisticated. The devices switched to the technology of image intensification and were compact enough that they could be worn above the head. 

Currently, there are 2nd generation NV devices that are widely available to be used by civilians. Nevertheless, both police forces and the military have advanced their NV technology. Apart from technological advancement, the NV goggles are also based on the technology of image intensification and work on that same principle. It’s the utilization of the light emitted by surrounding environment, connected with the technologies of image intensification.

Regardless of the current technological advancement in night vision, always remember that the very same original concept that was utilized during the conflicts aforementioned, continue to remain at its basis. 

What is the idea with the green image?

There are 3 kinds of technologies utilized in the night vision cameras, scopes and goggles. Thermal imaging is the first technology used in NV devices. Thermal imaging detects the difference in temperature between the foreground and the background. 

Active illumination tech is the 2nd kind of technology used. This technology joins image intensification with the illumination source in the nearby infrared band. In addition, the 3rd one is image intensification which explains why the night vision images us green. This technology of image intensification offers us that popular green light in Night Vision goggles and other devices. 

 Image intensification tech maximizes the light amount received from various natural sources like moonlight or starlight. It then ‘amplifies’ that light inside the NV devices to give us the most clear image possible. Sadly, this simply means that NV goggles using this technology cannot work in total darkness because it does not actually amplify light. Instead, it illuminates light up to levels that are detectable by human eyes. When the photons hit lens in front of NV goggles, they’re still carrying light of all the colors. However, once they turn into electrons, photons lose that information. As a result, the color of the incoming light is converted into white and black. But our question remains, why is the color of NV green?

The 1st reason is that the screen of image intensification in a night vision device is made up of Phosphor. Phosphor is used due to its luminance effect. In addition, when phosphor is struck by the electrons that do not carry the information of color, it glimmers bright green. Green phosphor is mainly used due to the fact that human eyes are extremely sensitive to green color pallets. 

In order to understand how the color sensitivity functions, you can have a look at a chromaticity diagram at www.agmglobalvision.com. The chromaticity describes a color’s quality that is determined by purity and dominant wavelength whereas a chromaticity diagram displays a range of the colors that can be seen by a human eye, mapped from green to blue to red. If you look at a chromaticity diagram, you’ll realize that the green color is more prominent than the other colors. In addition, the green color is easier to look at for a long period of time. This is also the reason why the early models of computer screens used to be green.