Night vision technology has been around for decades and has come a long way from its original concept. Four generations are available: Gen 1, Gen 2, Gen 3, and Gen 4. Each generation of night vision technology has unique features and capabilities that make it suitable for different applications.
What is the difference between the generations of night vision?
Generations of night vision differ in design features and assembly materials. By changing the design and materials, the parameters of night vision tubes change. Each generation has its range of possibilities. When choosing a night vision binocular, night vision monocular, or some other product from the night vision line, we expect a certain detection range, image quality, and a specific list of functions. Understanding what each generation has to offer helps you make your choice faster. In this case, the degree of illumination and resistance to light sources is worth considering.
Gen1 can only work on bright nights and requires backlighting. Third-party lights cause the screen to bloom. Gen2 operates in light clouds and starlight. Can do without a backlight. Feel free of side lights. Gen3 works with many clouds in the starry sky without a backlight. Excellent performance in urban environments. The Gen4 is perfect in every way.
Gen 1
First Generation Night Vision is the oldest technology that provides basic image enhancement capabilities. Amplification is possible up to 1000 times under illumination of at least a quarter of the moon. Gen 1 only works in active mode and requires infrared illumination. Under these conditions, we can expect a sharpness of 25-45 lines/mm in the center of the image. It should be noted that with better reproduction in the center, there is image distortion at the outer border and fuzziness and blurring of the contours of objects. This disadvantage narrows the field of view and affects the shape of things, somewhat stretching them at the edges. Of the characteristic features, we highlight the sensitivity to flare. If there are side or random light sources, we see “blooming” spots on the screen.
Gen1 has more blotches and digital noise than all the more recent generations. Its service life is designed for 1500 hours, much less than all subsequent generations. Gen 1 appliances are less versatile. For example, thermal monocular Gen 1 cannot be mounted on a weapon as a sight, in front of the sight, etc.
Despite several limitations, the first generation of night vision is the most affordable and common. It copes well with a range of up to 75 yards and performs trivial tasks.
Gen 2
The 2nd generation of devices using night vision technology has significantly increased the light amplification factor to 25-50 thousand. This became possible due to the appearance of an amplifier in the form of a microchannel plate. In this generation, there are night vision binoculars with and without an accelerating camera. The latter is more compact and weighs less. Light amplification occurs using a more sensitive, multi-alkaline cathode with a shift in the infrared region. Thermal goggles without an overclocking camera produce a better image with excellent contrast and clarity. In addition, they last longer and have less noise and interference in the images. Tubeless is labeled Gen2+; with a camera, one is labeled Gen 2.
Thermal vision Gen2 can operate without infrared light, even in the absence of the moon, in the light of stars and light clouds. This gave the amplest opportunities for covert surveillance and contributed to the spread of night vision sight, monoculars, and night vision binoculars in law enforcement agencies and armies worldwide.
Night vision goggles Gen2 have an excellent picture across the entire field without geometric distortion. The clarity of the image ranges from 32-45 lines/mm, depending on the generation subspecies.
Gen 2 and 2+ handle most tasks, from hunting to tactical action, and are still accessible to most users. Among the undoubted advantages, protection against side illumination, automatic brightness control, and increased recognition distances up to 200 yards are worth noting. The signal-to-noise ratio ranges from 12 -22, depending on the subspecies and model. The service life is awe-inspiring, 5-10 thousand hours. A slight glow effect around the light source can be distinguished among the shortcomings, but the result is insignificant.
Gen 3
The Gen 3 generation is practically the pro league and the best available to the civilian buyer. It differs from all other ages by working without illumination on a starry night with significant cloudiness. Moreover, they work ideally both in urban conditions and in the field. Compared to Gen 2, the third generation of night vision has a better image quality with minor, single interference. They differ from the second generation in an immense light amplification of 30-35 thousand conventional units and a longer helpful range of 300 yards.
Night vision equipment of the 3rd generation works on an image intensifier tube with a microchannel plate and a GaAs photocathode with a built-in power supply. If we compare alkaline and GaAs cathodes, the latter gives more favorable parameters. They include a resolution of 51-64 lines/mm, a signal-to-noise ratio of 18 – 24, and a service life of up to 10 thousand hours.
Hand-selected 3rd generation tubes have higher performance and are supplied mainly for the needs of the US military and security agencies. For example, the signal-to-noise ratio is 25-30; resolution – 64 to 72 line pairs/mm. Such instances give the most transparent, contrasting, and detailed image of all possible options.
Thermal goggles Gen3+ are not afraid of side illumination due to using an auto strobe system. This made it possible to protect the device from excessive light and energy load and rationally use the battery charge.
Of the shortcomings, the high price and the ban on export abroad are worth mentioning.
Gen 4
At first glance, it isn’t easy to improve the high-tech devices of Gen 3, but the scientists took a non-standard path, and instead of complicating the system, it was decided to simplify it. The 4th generation of night vision devices with the code “Unfilmed” was released. The scientists proposed to remove a thin ion-barrier film on the membrane from the previous Gen3 and leave the GaAs cathode and auto-gating system.
Thermal goggles Gen 4 are characterized by a 64-72 lp/mm resolution, a signal-to-noise ratio of 25-30+, and a detection range of over 300 yards. A gain of 50-80 thousand is a reasonably high figure for night vision devices. Those parameters that were only sometimes met in the 3rd generation and were selected manually became standard in the 4th generation. As a result, all indicators skyrocketed, and we got a product with an increased detection range and excellent image clarity.
The Thermal goggles Gen 4 excels on city streets at night with lighting and in fairly dark areas outside the city. It does not have a halo around glowing lights, the screens endure light without damage, and the flexible brightness system has proven itself very well.
For the sake of fairness, it should be noted that there were often failures of equipment based on filmless versions, and gadgets with a super-thin film are now being produced, giving a more stable result. So far, both modifications are being tested in the US Army and are unavailable to the general public.
White Phosphor Technology (WPT)
White phosphorus technology appeared in the days of Gen 3 in the helmets of combat aircraft pilots. Instead of the usual green phosphorus, white was used. The result was an image in grayscale with increased contrast and greater visibility, allowing you to respond to a changing environment quickly. Based on the results of the tests, it was concluded that most operators chose white instead of green phosphorus. They attributed this to greater comfort and reduced visual fatigue. Many found gray to be a more natural medium for the night than green. On average, after 4 hours of observation in NV devices with green phosphorus, the eyes were tired. Operators of night vision goggles experienced the same degree of visual fatigue with white phosphorus, but after 10 hours. Some respondents noted that spatial distances are better read in night vision binoculars with white phosphorus. In addition, gray images have a less pronounced “halo” effect and are sharper.
It is worth noting that the data cannot be interpreted unambiguously due to the difference in color perception by human vision. Therefore, when choosing night vision equipment, you should give preference to your feelings and not rely on others.
The variety of night vision devices strikes the imagination of beginners and professionals. The complexity of the design and the list of features grows with the generation of gadgets. The higher the age, the better the image quality and detection range. As the generation grows, NV devices allow you to see in poorly lit places, and IR illumination becomes optional.
NV devices of the 1st generation are suitable for beginners for performing simple security and surveillance tasks at short distances for large targets. They are budget-friendly and can easily cope with everyday problems. The second generation will suit most users, from police officers to bird lovers. The capabilities of the 2nd generation allow you to solve the broadest range of tasks but are still available. The third generation is a serious professional tool with many features and a price to match. The 4th generation NV is undergoing a process of improvement and is available only to a limited circle of the military. However, we do not recommend chasing the latest developments. A rational approach and testing will help narrow the list to a few models. And already among them, it is worth choosing the color of the phosphor coating.
