is common, that to make a right choice is generally not an easy task.
Currently there are hundreds of different types of models of night
vision devices from different manufacturers on the market. The reading
of abstruse instructions with manifold technical information brings no
new insights for the inexperienced buyer. From time to time the
uninformed purchaser may be misled by excessive and unrealistic (not
uncommonly 5 – 100 times higher) product performance figures, which are
for bait advertising only.
following information includes basic knowledge about night vision. The
intention is to support the night vision interested purchaser and offer
him a better knowledge in this specialty area – to make a right choice.
We are also always grateful to help you with any technical questions or
practical operating issues, personally.
night vision devices (residual light intensifier) operate on a basis of
multiple amplifying of available light sources at a visible and
near-infrared wave range. The night vision device consists of a lens, an
image intensifier tube (tube), a power source and an ocular. The
available ambient light (residual light) which is emitted by the
observed objects gets through the optical- lens, further through the
entrance of the tube on a plate with a photosensitive layer (cathode) by
what the image of the observed object is formed. This image is
electrically amplified and projected in the vacuum chamber on the output
side of the tubes phosphor layer (screen). The result is a
greenish-yellow optical picture, which gets through the lens to the eye
of the observer. Only a few high-tech tubes (ONYX™ – Technology) operate in a natural black/white modus.
is the alternative black/white night vision technology. Several studies
have shown that observed happenings at night are looking more natural
by using the black/white technology, instead the usual green one. The
black/white technology is invented for those, who value a less eye
stressing night observation. This black/white technology is more precise
and clearer by transmitting information such as contrast, shapes and
the qualities of a night-vision device are determined by the tube and
the optical system. Compatible with the introduced terms there are
differences among the types of tubes of Generation I, Gen. II and Gen. III (with subdivisions Gen. I+ and Gen. II+). Whereby the tubes of the European production (PHOTONIS) are not entirely matching the classifications (Gen. I, I+, II, II+, III),
which were introduced by the USA (ITT). Therefore this (European)
production has to be considered separately, because the European
developers stroke another way and developed their own advanced
technologies (CommGrade 1441/1451, CommGrade ECHO, SuperGen®, XD-4™, XR5™).
figure of merit (FOM) is used to determine the performance of a tube.
This value is easily calculated for all types of tubes from known
measured values. It provides a very distinctive insight in the
performance and quality of all modern types of tubes. This parameter is
used by the US authorities for determining the exportability of a tube.
It means that the US export of tubes with a high FOM value is regimented
and limited, since this value precisely defines the military advances
and the performance of the tube.
The FOM value is calculated in the following manner: S/N x lp/mm (S/N = signal to noise ratio). The FOM value is able to reach currently* a rate of 2000, by Gen. II, Gen. II+, ECHO, SuperGen®, Gen. III, XD-4™ and XR5™. It is an extreme high value, but not the maximum (PHOTONIS is able to reach a value of 2340 with XR5™ tubes – this value is a peak currently*
around all types of tubes. The purchase of this technology is only
possible for a few state security institutions, which have no
restrictions and posses an unlimited budget). The FOM value varies from
one tube to another. Many good tubes have currently* a
FOM value of app. 1600. But also tubes with a considerable lower FOM
value can be of excellent quality. Thus, the FOM is only one of many
other parameters. Therefore it is very important whether the tube is
individually meeting the requirements and if the advisory service for
the customer is designed in a fair way. Thus, tubes with a very high S/N
value and a very high resolution (lp/mm) have the highest FOM value.
Some FOM value examples for PHOTONIS tubes from our range:
(* state: 2019-02-01)
Image Intensifier Tubes of
The Generation I
tubes posses a glass-vacuum chamber with a cathode photosensitivity of
120 – 250 µA/Lm, at 2850K. The light amplification of such type of tubes
is between 120 – 900 times, the resolutions of pairs between 25 – 35
lp/mm (Development from the middle of the 1950s).
This type of devices that are equipped with Gen. I, you may find on the market for app. 300 EUR. A specific characteristic of the Gen. I
devices is, that the reproduced image is only sharp in the middle and
distorted at the borders of the observation image. Especially if diverse
light sources like flashlights or illuminated windows emerge in the
field of view – the whole observation image is overexposed and the
observation is utterly impossible.
their manufacturing, the tubes are classified within their
Generation-categories in quality grades (A, B, C and not successful
manufactured tubes with grade D). This division is reflected in the
prices of the tubes. This explains why, similar devices of the same
generation category of various manufacturers are offered at different
prices. The division in diverse quality grades is based on
photosensitivity of the cathode, resolution and clarity of the image.
The little black dots should not be disturbing for the observer in the
darkness, wherefore the purchaser should not criticize this
characteristic. In contrast, devices with bright and permanent shining
points or with a bright spot in the middle of the image are unsuitable
for a good observation – please do not buy these products.
is not recommended to purchase low-contrast tubes with a dull and
blurred image. The purchaser may understand and recognize whether the
image is clear or spots loaded, but only a trained eye is able to
ascertain the photosensitivity of a device – which in fact is the major
criteria. The photosensitivity is tested under realistic nighttime
conditions, by comparison of various devices.
Due to the low amplification, the single-stage (single-stage = 1 tube, multistage = 1, 2, 3 tubes built in a row) Gen. I
devices are depending on the light intensity of the optics and on the
performance of the tube. Only devices with high-quality tubes in
connection with especially light sensitive optics (relative aperture not
higher than F1.5) are able to ensure an optimal observation during
twilight and total darkness with ¼ moonlight. At lower surrounding
illumination the night vision device (image intensifier) requires an
additional light source, an IR-illuminator. Very good Gen. I
devices have an automatic protective function against high increase of
the overall lighting level, thus this function counteracts the wearing
of the tube when suddenly intense light sources appears or the device is
unintentionally switched on at daylight time.
increase the performance a number of tubes are placed in one case
(multistage devices). The light amplification of a three-stage-device
can be app. 20000 up to 50000 times higher. However, through this
procedure strong distortions occur and the resolution on the edges of
the image decreases intensely. Multistage devices are unhandy and heavy,
that’s why they have been almost forced out of the market by devices of
the Gen. I+ and Gen. II. Devices of the Gen. I+ and Gen. II have an obviously better performance and are only a bit more expensive then the multistage devices of the Gen. I.
Gen. I+ tubes a further development of the 1st generation (development from the end of the 60s). In the construction of Gen. I+
tubes a fiber optics slice is placed at the input (sometimes also at
the output) instead of a flat glass – thereby the resolution of the tube
is increasing substantially, the shape-distortion is being reduced and
the anti-dazzle function from lateral dazzling effects increased.
types of tubes are characterized by a light amplification of app. 1000
times, the photosensitivity of the cathode is at least 280 µA/Lm at
2850K and the resolution of the line pairs in the centre of the image is
between 45 – 50 lp/mm. The difference between devices with Gen. I+ tubes and their previous model with Gen. I
tubes, is a clear and pleasant picture, low self-noise and a greater
observation distance – in the passive and active state (using the
IR-illuminator). These Gen. I+ devices are preeminent
applicable in urban areas. Additionally, by natural light (residual
light) are such devices applicable up to a limit value of ¼, of the
natural moonlight. The price of a Gen. I+ tube is only app. 4 up to 9 times higher than the price of a Gen. I tube.
Image Intensifier Tubes of
The Gen. II tube differs constructional from the Gen. I+
tube due to the presence of a special electron-amplifier – microchannel
plate (MCP), which is placed between the cathode and the phosphor layer
(screen) (Development of the end of the 60s). In such a tube, the
electrons are multiplied by a very high quality, high-class
micromechanics (with 8 – 12 millions channels of only 18mm diameter
effectiv area). The effort necessary to produce such a high-class tube
is reflected in the price of it. By manufacturing a Gen. II, II+ tubes a Multi-Alkali cathode is exclusively used.
The Gen. II+
devices have no acceleration chamber. The tubes are characterized by a
light amplification of app. 25000 up to 35000 times, the
photosensitivity of the cathode is at least 500 µA/Lm at 2850K and the
resolution of the line pairs in the centre of the image is between 39 –
45 lp/mm (Development of the end of the 80s). Life expectancy of Gen. II+ tubes is around app. 1000 up to 3000 hours. Due to the absence of acceleration chamber is the light amplification by Gen. II+ tubes lower then by tubes of the Gen. II. By the difference in the photosensitivity of the cathode and particularly higher sensitivity for infrared light, the Gen. II+ devices are prove to be better than the Gen. II
devices by natural light (residual light). If the main task of the
night-vision device is to shot photos or/and videos, it is advisable to
choose a Gen. II device with a higher light amplification. All devices of the Gen. II and Gen. II+
have an automatic brightness control (ABC) for retaining the equal
brightness by changing of the ambient light (residual light), as a
automatic protective function by intense increase of the overall level
of illumination, bright source protection (BSP) for blooming-protection
of strong punctual light, as well as high image quality without
distortions over the entire screen area.
Gen. II and Gen. II+
devices belong to professional night vision and are currently in the
military use, because these devices are able to operate during very low
ambient light (residual light) – which can be compared with a starry sky
or even partly clouded starry sky.
Image Intensifier Tubes of
Generation III = ECHO, SuperGen®, XD-4™, XR5™
Gen. III tubes differ from the Gen. II+ tubes by their construction of the cathode. Gen. III
tubes have a Gallium-Arsenide cathode (GaAs) with more sensitivity for
IR-light. The light amplification is around app. 30000 up to 55000
times, the photosensitivity of the cathode is around 900 – 1600 µA/Lm at
2850K and the resolution of the line pairs is 32 – 64 lp/mm (omnibus 1
and omnibus 2 where developed end of the 70s, omnibus 3 and omnibus 4 is
a further development of the late 80s. Omnibus 7 is currently* the most powerful Gen. III tube with a FOM value of app. 2300). The performance of Gen. III tubes may vary, depending on type and specifications (omnibus 1 up to currently* 7 Pinnacle), by circa 300%. The life expectancy is around 10000 up to 15000 hours, which is 3 – 4 times longer than the Gen. II tubes. Devices with Gen. III
tubes are operating excellent in extremely low ambient light (residual
light). The observation image is saturated, sharp, with excellent
contrast and recognition of also smallest details. ECHO, XD-4™ and XR5™ tubes with an AUTO-GATING function are excellent suitable for operations in urban area.
is a special control electronics solution that is able to switch the
tube on and off with a very high frequency, which is imperceptible by
the eye. This innovative function allows the observer to operate in
bright ambient light, or even in daylight operations. By keeping the
full capability and performance, this function provides an efficient
wear- protection of the device. Furthermore this electronic solution
eliminates the glare of the light source by maintaining the performance.
Moreover, this function meets the high tactical requirements – for
instance by operating under bright lighting conditions such as military
operations in urban terrains which define many of today’s missions. This
special control electronic solution prevents blending and shadowing by
variant types of light sources or fire and helps to minimize the
abrasion of the tube.
vision devices optics consists of a lens and an ocular. The major
requirement on a lens is a high light-transmitting function of the
visible and invisible range of the IR-light. This light-transmitting
function is expressed with the figures of the F-numbers (relative
aperture), for instance F1.0, F1.4, F2.0, F2.8, F4.0, etc. On increasing
of the figure by one the lens is transmitting 2 times less light. A
high relative aperture (lower figure of the F-number) is a very
important factor for a night vision device, especially for night vision
devices of the Gen. I and Gen. I+. The consequence of a
lowering of the relative aperture until a value of F2.4 – F2.8 is that
the naked eye perceives more than a night vision device of the Gen. I
with a switched-on IR-illuminator.
development and the subsequent production of optics with a low F-number
F1.5 (high relative aperture) is a very difficult and expensefull task,
which cannot easily be managed by any company. Obviously the high costs
of development and production are increasing the final price. In the
race for the uninformed customers many producers are using lenses with a
3,5 up to 5 times magnification, but a low light-transmitting for long
distances. It should be noticed that also two identical devices with
completely similar tubes, the device with a stronger magnification will
produce a lower-quality image than a device with a lower magnification.
The range in the near surrounding area (residual light area) is shorter
than by using a device with a lower magnification – but with a higher
fact is especially relevant for night-riflescopes. In some cases the
producing companies are using a mirror-object-lens, which is reducing
the dimensions of a night vision device but has significant
disadvantages – the disguising (coverage) is not ensured, due to the
fact that the mirror-object-lens is mirror based and also the
light-transmitting is much lower under comparable conditions.
construction of the ocular has no impact on the range of the night
vision device, but is very significant for the observation properties.
For instance, a simplification of the construction of the ocular leads
inevitable to a shape-distortion of the observed object and a low
resolution on the edges of the image. The oculars of some manufacturers
are able to produce only a part of the whole field of view, although the
tube is a major and a most valuable component of a night-vision device.
It is very significant for night riflescopes, that the ocular
construction has an eye distance which is not less than 40mm, to prevent
injuries in the eye region from the recoil force of the weapon. The
ideal eye-ocular distance of a night riflescopes should not be less than
40 – 45 mm. It is also by no means irrelevant that an eye-ocular
distance of 40 – 45mm provides a much better quality of photography and
Most night vision devices have highly developed glass optics. The exceptions are inexpensive Gen. I
night vision devices with plastic optics and also some civilian types
of devices from leading manufacturers. Obviously the quality of devices
with plastic optics is much lower than the quality of devices with solid
civilian night vision devices posses a built-in IR-illuminator, which
provides the opportunity to illuminate the observed object, if there is
not sufficient ambient light (residual light) to perform an observation
in a passive state (without IR-illuminator). IR-illuminators are
produced as laser, LED (Light Emitting Diode) and special incandescent
lamps. It is important to note that laser illuminators may cause eye
damages and the sales are regulated in some countries by the law.
LED IR-illuminators are harmless for the eye.
the night vision device does not have a built-in IR-illuminator, it is
possible to use an autonomous IR-illuminator. The most producers do not
point out that the performance figures they supply are only the input
power. The input power of a device is not equal to its output power.
Thus, a IR-illuminator with 75mW output power radiates physically 70%
more IR-light than a IR-illuminator with 75mW input power. This fact is a
key factor for using a night vision device (image intensifier) in
active state (with IR-illuminator).
some night vision devices a 900nm IR-light wave range illuminators are
used. Their radiated light is not visible for the human eye and for the
eyes of the most wildlife species. Such devices are used by military- or
police operations, to preserve the coverage.
night vision device is more attractive for the customer, the smaller,
lighter and the longer range it has. However, are these demands partly
contradictory. A longer range, for instance, can only be achieved by
using a device with a larger lens (diameter). The choice is finally left
to the customer.
worth mentioning is the construction of the night riflescope. The
construction has to be shock resistant at 500G, thereby the reticle
should be fixed, should not shift from its initial position and has to
be remaining visible under all possible circumstances. A whole series of
civilian devices for hunting, which recently were placed on the market
do not meet the requirements of shock resistance by using heavy calibers
like .338 Lapua Magnum, .50, .416Rigby. The construction of mentioned
devices often does not provide the opportunity for mounting on various
types of hunting rifles. Also a miserable constructed
correction-mechanism or an incorrect mounting often causes a shift of
the point of impact. So there are countless characteristics and special
features in the construction and application of night riflescopes, thus
it seems to be impossible to briefly introduce all of them in this short
description. We highly recommend you not hesitate to contact us if you
have some additional questions regarding this subject. We are pleased to
give you further assistance.
user of night vision should take into account, that the observation
range and the detection of the observed object is depending on the
ambient light (residual light), the density of the atmosphere and on the
contrast of the observed object and its background. At elevated ambient
light (residual light) in a moonlit night or by using additional light
sources, the observation- and detection range increases if the
background of the observed object is bright – i.e. sand, snow etc.
According to that: at low ambient light (residual light), higher density
of the atmosphere and a dark background (loam, logs etc.) – the
observation- and detection range decreases significantly.
In the table the average observation- and detection range of a human body with a contrasty background are displayed:
the purchase it should be clarified, regarding values mentioned above,
which generation of the devices for which nature of task should be used.
With sophisticated technologies the fields of application increases,
but also the purchase costs grows accordingly.
hope that we could support you by choosing a right night vision device,
with this brief and simple description. After you made a correct choice
and have purchased the best suitable device for your tasks, you will
discover with fascination the possibilities of this modern technique is
able to offer.
If you have any further questions please contact Alpha Photonics. We give you a detailed and fair advice.
How far can I see at night?
There are many variables to consider that can affect visible distance with a Night Vision device. First, what are you trying to see? The larger the object the easier it is to see. What are the lighting conditions? The more ambient light you have, the more you will be able to see. You can always see further under moon and/or starlight. Generally, you should be able to tell the difference between male & female figures at around 75-100 yards. Remember – Night Vision Technology is meant to help you see in the dark, but not necessarily long distances like with binoculars.
What’s the difference between night vision and thermal?
Night Vision operates on the principle of light amplification; Thermal Imaging is a technology that creates a photographic image or video sequence of light emitted by an object at terrestrial temperatures (Heat Signature).
What does “autogated” mean?
Auto-Gating constantly operates to improve the quality of the image, not only during day-night-day transition, but also under dynamic lighting conditions.
When the power supply is “auto-gated,” it means the system is turning itself on and off at a very rapid rate. This, combined with a thin film attached to the microchannel plate (an ion barrier) reduces blooming. While “blooming” can be noticeably less on systems with a thin film layer, systems with thicker film layers can be perfectly acceptable depending on the end user’s application. Deciding which night vision goggle is better should not be based solely on blooming.
What is Manual Gain Adjustment?
Some of the scopes you will for sale on our website feature Manual Gain Adjustment. This control knob basically gives the user the ability to increase the “gain” or electronic amplification of the video signal. The intensity of voltage delivered to each individual pixel is increased and the result is a brighter image. If the scope does not feature Manual Gain Adjustment, then the scope utilizes some form of automatic gain that attempts to compensate for different environments of light exposure.
Automatic gain is generally acceptable for normal use. There are times however when some users find that an automatic gain setting “over” or “underexposes” an image and Manual Gain gives them the option to adjust for the best image. It should be noted that one side effect of increasing the Manual Gain too much is that the image noise increases (becomes grainy).
Why don’t you sell “generation 4” and what are “filmless” generation 3 tubes?
Most of our Generation 3 tubes are now available in a filmless tube version. Research innovators have now perfected the latest step in night vision technology by removing the ion film barrier within the night vision tube. Previous attempts at removing the film were inaccurately dubbed as “Generation 4” technology by a major company within the industry. In truth, the U.S. military contract was terminated because the process left the tubes too fragile for normal use. Now that the manufacturing process has been perfected, a robust Generation 3, filmless tube is available. The result is a more crisp image with less “halo effect” around bright lights, greater light sensitivity, and generally a greater signal-to-noise ratio.
There are four Generations of night vision; however, they are Gen 0-3, not Gen 1-4. Historically, the U.S. Army has defined each Generation of night vision. In the late 90’s the Army did define Gen 4 as the removal of the ion barrier film creating a “filmless” tube. This new advancement was to reduce halos while increasing sensitivity, signal-to-noise ratio (SNR) and resolution, for overall improved performance. While performance was improved, the lack of an ion barrier in Gen 4 tubes led to high failure rates, ultimately leading the U.S. Army to recant the existence of the Gen 4 definition. Now that we’ve seen the latest advances in filmless tube manufacturing, the Army has still not reapplied a “Generation 4” designation. We caution customers to be aware of advertising gimmicks from other companies that label their products as Generation 4 because they’re not being entirely genuine. However, if there truly was an official “Generation 4”, the filmless tubes would receive that rating.
What are White Phosphor tubes and is the black and white image better than the traditional green color?
Recently, night vision tube manufacturers developed a white phosphor tube which projects in black and white. Gradations of black and white are preferred over the traditional green color by many who report the new white phosphor tubes are less straining to the eyes during extended viewing and users are able to detect a greater range of detail and contrast over green. Customers occasionally report that they find the white phosphor tubes to be less bright initially. After a few minutes however, their eyes adjust and they’re able to see greater contrast. When they look away from the eyepiece, they report less temporary night blindness which is more noticeable with green tubes.
Why do I need an Infrared Illuminator?
An IR Illuminator is an ideal aid for extreme low light conditions. It significantly extends the capabilities of weapon sights, observation devices, and photographic equipment. Infra Red (IR) Illuminators emit an infra-red light that is nearly invisible to the naked eye, but your night vision device can see it.
Because the performance of any night vision or low-light CCD device is dependent on ambient light, magnification, atmospheric transparency, and contrast between the target and its background, an addition of the right IR Illuminator can significantly enhance visual acuity and extend detection ranges.
Night vision devices are numerous; there’s goggles, monoculars, scopes, and binoculars. Binoculars and Goggles occupy the unique role of having two lenses to view through. This enhances your field of view and depth perception. What’s the big difference between the two? That’s what we are discussing today
Night vision binoculars aren’t as common as goggles, but in many situations are the superior options. Night vision binoculars can deliver a most consistent and easy to see sight picture at a relatively low cost. At least as far as night vision goes. Night vision binoculars are excellent tools to survey and observe for extended periods of time. Most are designed simply with a low magnification to save weight and size. There are night vision binoculars in almost every night vision generation.
Night vision goggles are the most dynamic option for night vision devices. They allow hands-free use and provide a wide sight picture for the individual user. Night vision goggles are what most people envision when they talk about night vision. Night vision goggles have two distinct eyecups that offer a wider field of view than monoculars, and greater depth perception. Like binoculars, there are goggles in most night vision generations.
Binoculars have a nice advantage when it comes to their ability to magnify an image. Night vision binoculars are nowhere near as powerful as daytime binoculars but offer anywhere from 3 to 6 power magnification. Magnification with night vision gets tricky due to limitations with the technology. Also even though they are lower powered devices night vision binoculars are often already larger than standard night vision goggles.
Night vision goggles cannot offer extra magnification due to their inherent design. Magnified goggles would be useless as goggles and simply be binoculars. Binoculars have an advantage if you need to see something at any real distance. Your range of sight is already limited due to night vision, so extra magnification can only help.
With a target at an extended range, a pair of goggles may reveal a moving blob of greenish light, but a set of night vision binoculars will allow you to tell if that green blob is a stray dog or a suspicious person.
Clarity is more about the generation, the quality of materials and manufacturers of the night vision goggles or night vision binoculars. One is not more intrinsically clearer than another just due to their different designs. This category is a clear tie and cannot be determined without comparing “like” with “like” and allowing the decision to be made on individual product levels.
Movements with either system will be easier than movements without. Night vision allows you to see things right in front of you, like holes, large brush, and other potential hazards. Night vision goggles are vastly superior for moving at night, and allow you to safely see where you’re going. Goggles also attach to hands-free systems that allow you to carry extra gear, and better maintain your balance as your tricky terrain, jump across small bodies of water, or if you need to climb. Binoculars do allow you to scout potential routes and identify hazards but are weak at allowing you to see what’s directly in front of you.
When it comes to simply observing an area for an extended period for any reason, binoculars are the better choice. They allow you to watch an area from a distance and makes seeing the details of that area easier. Binoculars offer a better sight picture than googles when observing a large area, with the ability to traverse to different distances with ease.
Binoculars allow you to also watch for more concealed positions compared to goggles which may force you to be closer than you want to the area you are observing. Regardless of the reason, you are watching an area a set of binoculars is easier to use than a set of goggles. Be it observing animals, or guarding a post.
Hunting at night is a controversial and occasionally illegal venture. Always ensure you are within your state’s hunting laws. However, with that said, night vision goggles do allow you to use and carry a firearm. The hands-free nature of night vision goggles makes them much easier to use when hunting. Night vision goggles, when paired with an IR laser on a firearm, is also an accurate way to engage your game of choice. Night vision binoculars would make spotting and watching animals easier, but they would make it more difficult to shoot them.
Off the bat, it’s very easy to assume goggles are the best tactical choice. They make carrying a weapon and moving possible. However, you have to examine the tactical situation. In a dynamic and flowing situation like an airsoft CQB match, a set of goggles is the superior choice. It allows easy movement, easy shooting, and a hand’s free experience.
However, on the other side of the tactical hand, not all situations are fast moving and dynamic. A police officer surveilling an objective is way better suited with a pair of binoculars that allow him to park a good ways away.
How to determine the two will be easy. Look at the needs you have and identify which product works well for you. At the end of the day, it’s going to boil down to the objective at hand and what you’ll be doing.