Night vision devices (NVD) are unique modern gadgets that amplify the light in low light conditions and complete darkness, boosting the infrared illumination from IR lamps. Since these devices amplify the morning, we see bright spots from the lanterns in the background. Night vision is used in various fields of activity, from conventional CCTV cameras to night vision scopes. The main difference between all night vision devices is the technology used and the generation. Night vision technology has undergone several waves of scientific and technological progress over the past 80 years. Today, the market for NVD offers devices that operate on the same principle used by the US military in the 60s of the twentieth century.
It should be noted that most night vision devices use a green background to display the picture by default. And this was done not out of the developers' whim but for practical reasons. The physiology of the human eye allows you to capture the most significant number of green shades.
The only thing that has changed since then is the digital transformation of technology: analog NVD has been replaced by digital ones. Consequently, several generations of night vision goggles emerged during this period. These generations are classified as Gen1, Gen 2, Gen 3, and Gen 4. Of course, the scientific literature tells in more detail about the difference between all generations while using boring technical information, describing image intensifier tubes in detail (further EOP). But an ordinary person is unlikely to be helpful and interested in more information about ion barriers, microchannel plates, gallium arsenide, and photocathodes. For a regular consumer, it is enough to know that the main element of every night vision device is an image intensifier tube.
It is the modification of the image intensifier tube that significantly affects the quality of the picture. Based on the choice of one or another generation of image intensifier tubes, the price for the entire NVD changes dramatically. So, the abbreviation Gen2+ is deciphered as follows: Gen - generation, the number "2" is the serial number of the modification, and the "+" sign indicates the presence of an intermediate or, more precisely, an improved version of this generation.
What is the difference between the generations of night vision?
Let us consider in more detail the principles of amplifying the light of NVD. The focus of the operation of night vision devices is to boost the captured light hundreds and thousands of times. The entire spectrum of visible light lies in the range from 400 to 760 nanometers - this is the light that we can see, and radiation in the range from 760 nanometers is infrared radiation, which is invisible radiation for humans and animals. It is in the infrared spectrum that many night vision devices work. Next, we will study the generations and technologies of night vision devices in more detail.
Gen 1
Gen 1 is a generation of analog night vision goggles. For the first time, such devices were used by the US Army during military operations in Vietnam. The image intensifier tube of the first generation can amplify the image a thousand times. One of the main disadvantages of this generation can be called a dull image with low resolution. Another disadvantage can be considered a short service life - about 1500 hours. Gen 1 cannot be used in "passive" mode (without built-in infrared illumination). The first-generation night vision devices have a smaller viewing angle due to distortions that appear in case of excessive lighting.
Relatively recently, NVD Gen 1+ appeared. This is still the same analog device, but the converter's edge distortion problem has been solved. Sometimes such a device can be found on the Internet by adding the abbreviation CORE (Ceramic Optical Ruggedized Engine). Distance for work within 45-55 meters. However, Gen 1+ technology could not overcome the image amplification threshold of 1000 times despite all the innovations.
Gen 2
The appearance of the second-generation night vision devices was preceded by a qualitative scientific breakthrough in forming vacuum electronics components. The main element in the Gen 2 image intensifier tube is a microchannel plate, with which you can enhance the picture's brightness. The device's service life is about 2000-2500 hours, and the working distance is up to 183 meters.
Gen 3
The third generation uses a photocathode based on gallium arsenide, which made it possible to increase the sensitivity of NVD significantly. The working distance is approximately 275 meters), and the image amplification is from 30,000 to 50,000 times. The service life of 10,000 hours. Generation Gen 3 is considered the "gold" standard by experienced night vision users and is used by military personnel worldwide. Gen 3 is also divided into several subcategories:
Gen 4
Today there is no officially recognized classification of Gen 4. The term fourth generation of night vision devices is nothing more than a marketing ploy. Indeed, the updated image intensifier tubes were first called the fourth generation. However, after a detailed study, it turned out that these were generation 3 image intensifier tubes, which received an improved performance by removing the ion barrier film. In addition, against the background of an increase in sensitivity, the service life of the image intensifier tube has sharply decreased - up to one thousand hours. This technology is referred to as Filmless Gen 3 or filmless. However, some manufacturers continue to use the term Gen 4 for promotional purposes.
White Phosphor Technology (WPT)
What if you have a question, is there night vision in white or black? It turns out that, yes, it could be true. This discovery is known as white phosphorus technology (WPT). Now on the market, there is a night vision device in white and black. One of the manufacturers of night vision devices recently presented White Phosphor Technology (WPT). This technology was developed after scientists agreed that night vision is much better perceived in the traditional black-and-white raster than in white-green-black. So, the details of the figures, contrast, and shadows are better perceived. WPT is the only one that delivers this clarity. Operators testing devices using WPT reported significantly better detail, overall contrast, complete moon likeness, and hue range. WPT provides sharper shades of intensity between white and black than between green and black, resulting in better contrast and depth perception than green phosphor NVG. Of course, the white luminophobic eras are already present in generations three and up. They have the best number of images and materials used to create the device. So, when viewed, an excellent picture is obtained with a high degree of detail, resolution, and contrast. An image with a green phosphor cannot provide such a picture. Although the human eye is more sensitive to green tint, WTT detail is capable of fast pointing.
Conclusion
In conclusion, it should be noted that the history of NVD is not limited to the level achieved. The continuous expansion of production and sales volumes and the high interest in new products on the part of all participants in the high-tech market testify to the broad prospects of night vision technology. Even though NVD with image intensifier tube III can perform tasks on the darkest nights, active work is currently underway to develop both generation IV night vision devices and improve the NVD's circuitry. Most of the work is related to enhancing ergonomic characteristics, design, and expansion of the functionality of devices.
And the expansion of the functionality of devices.