Starlight Technology Night Vision
Generations and Devices
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
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
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.
- 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
- 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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