Night vision systems help you see objects in a dark environment at night. But the question is, how does night vision work? How can a small tube show us something that our eyes can’t?

Before we strip the parts of a night vision device, you must understand what the gear does.

What are Night Vision Devices?

A night vision device (NVD) amplifies available light so you can see in dark or lowlight conditions. Although technology has evolved greatly since its introduction in the 1930s, the basic premise remains the same.

An NVD works by guiding light toward an objective lens, which then focuses this light onto an image intensifier. Then, a photocathode transforms the light into energy and directs it to a screen to produce a visible image.

How Does Night Vision Work: The Basics

Night vision technology enhances the faint ambient light that is usually invisible to our eyes, enabling us to see in low light or dark conditions. Night vision devices are categorized into different generations, each providing better performance (from Gen1 to Gen3, including Digital Night Vision). Night vision technology employs different types of image intensifier tubes, which transform faint light from the visible and near-infrared spectrums into visible light that the human eye can see.

This lets people see clearly in low light or complete darkness when using infrared (IR) illumination or surrounding ambient light. Night vision works by enhancing this ambient light as it passes through electron-charged intensifier tubes. All night vision devices are highly sensitive to light and could be damaged if exposed to bright sunlight, car headlights, or excessive direct light.

Understanding Digital Image Enhancement

Most night vision devices available today use a digital version of the classic optoelectronic image enhancement technology.

Digital image enhancement technology creates devices that are smaller, lighter, and much more versatile for night vision.

Using digital night vision technology, the light that comes into the objective lens is turned into a digital signal by a complementary metal-oxide-semiconductor (CMOS) sensor, similar to those found in digital video cameras.

This digital image is then electronically improved and greatly magnified before it is sent to an LCD screen for viewing. The bigger the CMOS sensor, the better the image resolution you get—many modern digital night vision devices can display and record full 1080p HD video.

NVD Generations

Just like all types of technologies, night vision devices, like night vision goggles, have gone through several different evolutionary stages to achieve their current level of capabilities and can be generally categorized into four distinct generations.

Gen 1

The Gen 1 intensifier tubes amplify light about 1,000 times more than the human eye. Still, the first night-vision generation does have its downfalls, which include blurry edges, low resolution, and dependency on infrared illuminators.

Gen 2

Generation 2 is brighter, has a sharper image, and more distinct imagery. It goes all the way up to what the military uses now, which is phenomenal. It’s all of the scales in performance and cost. Generation 2 enhances the older Generation 1 tubes within the device by incorporating a new microchannel plate to boost light gain and overall resolution.

It significantly improves the Gen 2 image performance but has roughly the same light sensitivity as the Generation One night-vision devices.

The second generation of night vision goggles has embodied a huge technological leap forward. The difference between the third and second gens is much less than between the second and the very first systems. More recently, night vision technology came onto the scene; unlike the generation models, digital models are not harmed by light exposure because there are no intensifier tubes.

Digital devices can also be used during the daytime. However, the quality is similar to that of the Gen1 device, and adding infrared illuminators helps make them more effective.

Gen 3

The Generation 3 devices became the next step up in night vision technology. Generation 3 is a great deal. Conventionally, representatives of the third level of development of night-level devices are divided into several classes. But, this division is very arbitrary because of the amazing capabilities of all classes.

They all provide the highest picture quality and are insensitive to interference, such as car lights, glare, house lights, etc. The third generation uses the same image transmission technologies as the second. However, the quality improves due to the tube photocard attached to the screen. The third type of night vision system has the brightest, sharpest, and increased tube life of up to 10,000 hours.

Those reasons make these devices very reliable, which is why the United States military currently uses Gen 3 devices. One caution when using Gen 1, Gen 2, & 3 NV devices is not to expose the internal tubes to daylight because they can burn out. So, the 3 Gen devices are great and will provide excellent performance on a budget.

Gen 4

There is also a Generation 4, but it’s something other than what commercial users can access. After presenting the so-called fourth generation, the army gladly recognized its status. However, practical tests that did not show compliance with high military requirements caused some disappointment, which led to the cancellation of recognition.

While this is by no means an extensive explanation of the differences between all of the night vision generations, I hope it has helped your night vision education process.

If you have any questions about how night vision works, please feel free to ask our team today. We also offer night vision devices for commercial aviation, military, rescue purposes, and a lot more. Please visit our website!