Generation Designations

Levels of night vision technology are known as generations. Each generation corresponds to a U. S. military specification defining components, performance requirements, and quality parameters. Night vision devices come in three accepted generations of design (Generation 1, 2, and 3). Other designations (Generation 1+, 2+, 3+ and 4) may offer improvements, but do not correspond to official accepted generations. These designations are not specifically defined, and the names are not consistently applied.

Levels of night vision technology are known as generations. Each generation corresponds to a U. S. military specification defining components, performance requirements, and quality parameters. Night vision devices come in three accepted generations of design (Generation 1, 2, and 3). Other designations (Generation 1+, 2+, 3+ and 4) may offer improvements, but do not correspond to official accepted generations. These designations are not specifically defined, and the names are not consistently applied.

Some manufacturers are also touting Generation 4 night vision devices. These have not been officially adopted by the military so the designation has not gained general acceptance. We will discuss this generation briefly below since it is likely that this designation will indeed gain acceptance and official military specifications (mil spec definition).

Generation 1 Night Vision

First Generation night vision devices are the most common and inexpensive consumer models on the market today. These devices have a great range of quality (more so than any other generation). To give a feel for price, Generation 1 monoculars range from about $100-$400. The differences in quality and features are extensive within this price range.

Generation 1 night vision was originally developed by the US military in the Vietnam War. These devices are also called “Starlight scopes” and were a tremendous improvement upon the Generation 0 devices, mainly through improvements in the photocathode.

Generation 1 devices certainly have their uses although the image distortions (discussed above under “Image-intensifier tube”), lower light gathering ability, and range in quality can discourage initial buyers from the technology.

Good Generation 1 devices, although significantly lower in light gathering ability than Generation 2 devices, gain tremendously in effectiveness with the standard incorporation of IR Illuminators. These units are often all that is needed for campers and boaters. General nature observation at night might also be comfortable with better models although the image distortions and low light-gathering ability make anything other than general behavior observation difficult.

The best performance is achieved in Generation 1 devices by using fully-coated all-glass optical elements. Units which incorporate plastic (composite) optics are not recommended.

Generation 2 Night Vision

The main design change between Generation 1 and Generation 2 night vision was the addition of the microchannel plate that we discussed above under the “image-intensifier”. The introduction of the microchannel plate significantly improved the light amplification ability of the devices. Multiplying the number of electrons provided a much brighter image. Forcing the electrons into a linear path as they flow through the microchannels ensures more orderly output and much less distortion in the resulting image. This also allowed there to be less charge in the intensifier tube, since acceleration was not the principle source of light amplification, resulting in increased battery and tube life.

The significant increase in capability of Generation 2 devices comes at a big jump in cost though. Generation 2 monoculars range in price from about $1000-$1500. Although this is a significant jump in price, the image quality, brightness and extended life over Generation 1 products make these a much more sensible investment for serious night vision users.

Generation 3 Night Vision

In Generation 2 designs, the main improvements came with the addition of the microchannel plate, but the photocathode had only minimal improvement. Generation 3 devices were substantially improved by changing to a new photocathode material - gallium arsenide. An ion barrier film was added to increase image-intensifier tube life. This, along with more improvements in the microchannel plate, gave Generation 3 night vision devices much greater light amplification abilities, better resolution and clearer images with less noise.

Once again these newer devices come at another significant jump in cost. In our price comparisons, we see Generation 3 monoculars running about $3,000-$4,000. Although they still benefit from the addition of an IR illuminator, the increased sensitivity of these devices allows them to be operated entirely passively outdoors.

Generation 3 night vision, because of the higher cost, is normally reserved for only the most demanding naturalists, researchers, police, Homeland Security, etc. They are such high tech instruments that both these and “Generation 4” night vision devices are restricted in sales and cannot be shipped out of the United States without special permits from the State Department.

Generation 4 Night Vision

Officially there is no accepted (by the military) Generation 4 night vision technology although the term is used/accepted among night vision manufacturers. The designation is widely debated and is referred to as Filmless & Gated image intensifiers by the US military.

The "filmless" terminology refers to the removal of the ion barrier film that was added to the Generation 3 image-intensifiers. This provides a higher “signal to noise” ratio (less "snow" in the image). The "gated" terminology refers to a “gated” power supply. This technology makes it possible to operate night vision devices during daylight (if necessary). It also improves the image resolution and minimizes halo from bright light sources. If, for instance, you have a distant house light in view the typical halo around the light is minimized and the overall image resolution is improved.

Once again this all translates into an even sharper view over Generation 3 night vision, even greater ability to see in very dark conditions and another jump in price. Our general price comparison of this technology shows monoculars running about $5,000-$6,000.

Types of Night Vision Devices

Night vision devices usually come as monoculars, binoculars or goggles (rifle scopes also for military and hunting applications). The night vision technology, defined above, remains constant and these basic types are only different configurations. Each configuration is a bit different and has its own strengths and weaknesses. Below we define each of these and give some basic information on their best applications and uses.

Monoculars (night vision)

In front is a conventional objective lens, which captures ambient light and some near-infrared light. This lens focuses the incoming light onto a photocathode at the front end of an image intensifier tube. The objective lens is adjustable and is used to focus at different distances similar to the focus knob on a pair of binoculars.

Binoculars (night vision)

Binoculars are similar to monoculars in usage only they have the advantage of having two eyepieces to look through rather than just one. There are two basic binocular designs for night vision: the first would be like a regular binocular with two eyepieces, two image-intensifier tubes and two objective lenses (like two monoculars hinged together). The second design type also has two eyepieces but only one image-intensifier tube and objective lens (the image coming out of a single image intensifier tube is split and directed with mirrors into two eyepieces). Again as with night vision monoculars the magnifications are reasonably low (2x-4x). They are also similar to monoculars in that they are best used for “stop and look” types of applications rather than while moving. The rules of higher magnification versus performance are the same as with monoculars.

Goggles (Night Vision)

The main difference between night vision binoculars and night vision goggles is that, in general, goggles are only one power (1x). Although some of the binoculars and monoculars have head mounts, in general these are difficult to use continuously or while moving around because the magnification conflicts with our normal depth perception. Goggles are hands-free and include a helmet mount or head mount. They are perfect for walking through the woods and generally looking around at night. They don’t have the advantage of magnification that brings objects into closer view. Some models, though, do have the advantage of removable head mounts and optional higher magnification lenses that can be added to convert the goggles into a binocular.

Conclusions

• The “Generation” designation is military specification that specifies the design of starlight technology night vision devices. This designation defines the level of sophistication of the design and your subsequent ability to see in the dark.
• Generation 1 devices are readily available and affordable but have limited abilities and noticeable distortions around the field of view. There are big variations in quality of these devices on the market.
• Generation 2 devices had major design improvements that significantly increased their abilities and reduced distortions although come with a big jump in cost.
• Generation 3 and 4 are so sophisticated that export is restricted from the US. These devices are powerful enough to use completely passively (without IR illuminators). The costs again take a big jump and these might only attract the most serious enthusiasts, researchers and law enforcement professionals.
• Night vision devices come configured as either a monocular, binocular or goggle. Each of these configurations has its own best application and use.

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