Wednesday, 23 of July "I never think of the future, it comes soon enough." - A. Einstein
TECHNOLOGIES HOW STARLIGHT TECHNOLOGY WORKS
Night vision devices gather existing ambient light
(starlight, moonlight or infra-red light) through the front lens. This
light, which is made up of photons goes into a photocathode tube that
changes the photons to electrons. The electrons are then amplified to a
much greater number through an electrical and chemical process. The
electrons are then hurled against a phosphorus screen that changes the
amplified electrons back into visible light that you see through the
eyepiece. The image will now be a clear green-hued amplified re-creation
of the scene you were observing.
1. Front Lens
4. High Voltage Power Supply
2. Photocathode
5. Phosphorus Screen
3. Microchannel plate
6. Eyepiece
FIRST, SECOND, THIRD AND FOURTH GENERATION
A Night Vision Device can be either a 1st, 2nd, 3rd or
4th generation unit. What this stands for is what type of light
intensifier tube is used for that particular device The light intensifier
tube is the heart and soul of an NVD.
1st generation is currently the most
popular type of night vision in the world. Utilizing the basic principles
described earlier, a 1st generation will amplify the existing light
several thousand times letting you clearly see in the dark. These units
provide a bright and sharp image at a low cost, which is perfect, whether
you are boating, observing wildlife, or providing security for your home.
You may notice the following when you are looking through a 1st gen unit
A slight high-pitched whine when the unit is on.
The image you see may be slightly blurry around the edges. This is
known as Geometric Distortion.
When you turn a 1st gen off it may glow green for some time.
These are inherent characteristics of a 1st gen and are normal.
2nd generation is primarily used by law enforcement
or for professional applications. This is because the cost of a 2nd gen
unit is approximately $500.00 to $1000.00 more then a 1st gen. The main
difference between a 1st and a 2nd generation unit is the addition of a
micro-channel plate, commonly referred to as a MCP. The MCP works as an
electron amplifier and is placed directly behind the photocathode. The MCP
consists of millions of short parallel glass tubes. When the electrons
pass through these short tubes, thousands more electrons are released.
This extra process allows 2nd generation units to amplify the light many
more times then 1st generation giving you a brighter and sharper image.
3rd generation By adding a sensitive chemical,
gallium arsenide to the photocathode a brighter and sharper image was
achieved over 2nd generation. An ion barrier film was also added to
increase tube life. Gen. 3 provides the user with good to excellent low
light performance.
4th Generation / Gated Filmless tubes: 4th
generation / Gated Filmless technology represents the biggest
technological breakthrough in image intensification of the past 10 years.
By removing the ion barrier film and "Gating" the system Gen 4
demonstrates substantial increases in target detection range and
resolution, particularly at extremely low light levels.
The use of filmless technology and auto-gated power supply in 4th
generation image intensifiers result in:
Up to 100% improvement in photoresponse.
Superb performance in extremely low light level (better S/N and EBI)
At least triple high light level resolution (a minimum of 36 lp/mm
compared to 12 lp/mm)
With significant improvement in contrast level and in performance
under all light conditions, 4th generation represents the top of the line
performance in the night vision market. Note: The term 4th generation is
used/accepted among Night Vision manufactures to describe gated filmless
tubes. However, this designation is widely debated and is currently
referred to as Filmless & Gated image intensifiers by the US Military.
Gen 4 technology improves night
operational effectiveness for military users of night vision goggles
and other night vision devices. The filmless MCP provides a higher
signal-to-noise ratio than Gen 3, resulting in better image quality
(less scintillation) under low-light conditions. The gated power
supply further improves image resolution under high light
conditions, and the reduced halo minimizes interference from bright
light sources. These improvements also substantially increase the
detection range of the systems.
Gen 3 Omni IV
Gen 4
% Improvement
Photoresponse (cA/Im)
1800
1800
-
Signal-to-Noise Ratio
21.0
25.0(ground)
20% Higher
26.0(air)
24% Higher
Resolution(lp/mm)
64
64
-
Halo(mm)
1.25
0.75
40% smaller
Reliability(hours)
10,000
10,000
-
RANGE IMPROVEMENT
Relative direction ranges
PVS-7 System
Overcast Starlight Conditions (-1x10E-5 tc)
Vehicle Size Target, 30% Contrast
Gen 2
SuperGen 2
Gen 3 OMNI I and II
Gen 3 OMNI III
Gen 3 OMNI IV
Gen IV
Detection Range (m)
170
270
240
290
360
430
% Improvement over Gen II
0%
60%
40%
70%
110%
153%
Gen IV technology is not currently available for
export.
XD-4 Image Intensifiers
The XD-4 is the top grade of the DEP Image Intensifiers.
With the introduction of the XD-4 technology a new European Standard for
low light imaging was born providing unprecedented performance in Night
Vision applications.
The XD-4 Image
Intensifiers perform extremely well in all environmental conditions.
Its wide spectral sensitivity range ensures that a perfect picture
is obtained regardless of the user’s environment (foliage, on water,
snow, desert, rocky and barren land) or light conditions (down to
heavily overcast starlight). The XD-4 Image Intensifiers provide
as well a superb image under very dynamic light conditions.
The basis for the unique performance of the XD-4 is the
technology used by DEP. This has resulted in greatly improved performance
parameters that are crucial for good observation, such as the
Signal-to-Noise Ratio (SNR), the Modulation Transfer Function (MTF) and
Resolution under all circumstances. Add to this the very long lifetime
throughout its complete luminance dynamic range and you will be convinced
of its unique performance.
The performance
parameters of the XD-4 Image Intensifier are listed in the table
below. Highlights of the XD-4 specification are the typical SNR of
24, the resolution of 64 lp/mm and over and - very important - the
high MTF at low and intermediate spatial frequencies. The latter
gives the image its sharpness and contrast.
It goes without saying that the XD-4 tubes can be
supplied in every common mechanical construction including inverting and
non-inverting fibre-optic output, which also means that users have the
opportunity to upgrade the performance of existing Night Vision Equipment
via a drop-in XD-4 Image Intensifier.
Technical specifications of XD-4 technology image
intensifiers:
Resolution
Minimal
Typical
Maximal
UNIT
Limiting resolution
Type I
55
58
lp/mm
Type II
60
64
lp/mm
Modulation Transfer Function:
2.5 lp/mm
92
%
7.5 lp/mm
80
%
15 lp/mm
58
%
25 lp/mm
38
%
30 lp/mm
30
%
Signal to Noise
Minimal
Typical
Maximal
UNIT
Signal to noise (@108clx)
20
24
Other Technical Data
Minimal
Typical
Maximal
UNIT
Phosphor: P20*
MTTF (to S/N=12)
15.000
hrs
Gain at 2.10-5 lx
30.000/p
50.000/p
cd/m2/lx
Max. Output Brightness
2
17
cd/m2/lx
E.B.I.
0.15
0.25
lx
Output uniformity at 2850K
2:01
3:01
Weight(18mm)
80
95
grams
Shock
500
g
Luminous sensitivity at 2850K
600
700
uA/lm
Radiant sensitivity at 800nm
50
60
mA/W
Radiant sensitivity at 850nm
40
50
mA/W
DEP Image
Intensifiers with XR-5 Technology
As a result of sustained and continuing product
development, DEP is proud to introduce the latest, innovative XR5 Image
Intensifier with unprecedented performance for any environment and any
circumstance.
The XR5 Image Intensifier, successor to the well-known
and successful XD-4 Image Intensifier, reveals even more details of the
night and offers an eXtended Range (XR) capability thanks to its new
technology.
Furthermore, the XR5 Image
Intensifier enables the user to see even more during a full 24-hour
day/night operation. This is done by the use of a fully integrated
Auto-Gating unit, which controls the image not only during
day-night-day transitions but also during dynamic lighting
conditions such as those experienced, for example, in night
operations in urban areas. In practice, this means no blooming to
hinder your mission but dependable imagery throughout. In addition,
the halo is the smallest on the market.
The XR5 Image Intensifier from DEP represents the new
European standard for Night Vision and is available in a variety of
inverting and non-inverting 18 mm formats.
The new XR5 is your
best choice to maintain your combat effectiveness under all circumstances.
Technical specifications of XR5 technology image intensifiers:
Resolution
Minimal
Typical
Maximal
UNIT
Limiting resolution
64
70
lp/mm
Modulation Transfer Function:
2.5 lp/mm
93
%
7.5 lp/mm
82
%
15 lp/mm
67
%
25 lp/mm
46
%
30 lp/mm
35
%
Signal to Noise
Minimal
Typical
Maximal
UNIT
Signal to noise (@108clx)
25
28
Luminance dynamic range
Minimal
Typical
Maximal
UNIT
Auto-Gating and Automatic Brightness Control
1.0E-06
5.0E+04
lux
Other Technical Data
Minimal
Typical
Maximal
UNIT
Phosphor: P20*
Reliability
15.000
hrs
Gain at 2E-05 lux
30.000/p
50.000/p
cd/m2/lx
Max. Output Brightness
2
17
cd/m2
E.B.I.
0.25
ulx
Luminous sensitivity at 2850K
700
800
uA/lm
Radiant sensitivity at 800nm
65
78
mA/W
Radiant sensitivity at 850nm
50
65
mA/W
Input voltage
2
3.7
volt
Input current
35
mA
Output uniformity at 2850K
1.8:1
3:01
Weight (18mm)
80
95
g
Shock
500
g
INFRA-RED ILUMINATORS
All Starlight
scopes need some light to amplify. This means that if you were in complete
darkness you could not see. Due to this we have a built in infra-red
illuminator (IRI) on all of our scopes. Basically what an IRI does is
throw out a beam of infra-red light that is near invisible to the naked
eye but your NVD can see it. This allows you to use your scope even in
total darkness. The IRI works like a flashlight and the distance you can
see with it will be limited. We do use the most powerful eye-safe
illuminator on the market. This allows our IRI to extend out to 100 yards
However, because of the power at a short distance the IRI may cover only
40-60% of the viewing area.
HOW FAR CAN YOU SEE
There are many different variables that can effect the
distance that you can see with a Night Vision device. First, what are you
trying to see Are you looking for another boat on the water or are you
looking for a rabbit in the woods The larger the object the easier it is
too see. Plus, are you trying to see details (what we call recognition
range) or are you just trying to see if something is there or maybe you
will just see movement but won’t be able to 100% determine who or what it
is. This is called detection range. Second. Another variable is lighting
conditions. The more ambient light you have (starlight, moonlight,
infrared light) the better and further you will be able to see You can
always see further on a night where the moon and stars are out then if it
is cloudy and overcast. We typically state that you can tell the
difference between a male and a female or a dog and a deer at about 75 to
100 yards. However, if you were looking across an open field and there was
a half moon out you could see a barn or a house 500 yards away.
Remember, that the purpose of an NVD is to see in the dark not
necessarily a long ways like a binocular.
BLACK SPOTS ON THE SCREEN
As you look
through a night vision device you may notice black spots on the screen. A
NVD is similar to a television screen and attracts dust and dirt.
Typically these spots can be cleaned. However, this may also be a spot in
the tube itself. This is normal. Most tubes will have some spots in them.
These black spots will not affect the performance or reliability of the
night vision device.
2005-07-20 Nature By Night By Graham Thomson When you are hiking along in the twilight you will probably notice various birds going to bed; indeed, often you cannot help but notice them, so noisy and fussy as they are! Have you ever heard a rookery settling down for the night in the high tree-tops? What a cawing! A lot of it sounds rather like ...
2005-07-20 Night Eyes By Graham Thomson Can you see in the dark, like a cat?
As a matter of fact, it is doubtful if a cat can see any more clearly in the dark than any other animal, though it is quite likely that it can, because its eyes have such large pupils. These collect every faintest ray of light reflected by objects round about, and ...
2005-04-19 Night Hunting by Randy Watson We were both huffing and puffing when we finally got to a rise in the darkness that seemed like a good vantage point. It was hard to tell, judging only by feel. It was two in the morning, we had been poked by mesquite thorns and stumbled along in the night for better than a half hour. We could finally ...
Gen 4 technology improves night
operational effectiveness for military users of night vision goggles
and other night vision devices. The filmless MCP provides a higher
signal-to-noise ratio than Gen 3, resulting in better image quality
(less scintillation) under low-light conditions. The gated power
supply further improves image resolution under high light
conditions, and the reduced halo minimizes interference from bright
light sources. These improvements also substantially increase the
detection range of the systems. 
All Starlight
scopes need some light to amplify. This means that if you were in complete
darkness you could not see. Due to this we have a built in infra-red
illuminator (IRI) on all of our scopes. Basically what an IRI does is
throw out a beam of infra-red light that is near invisible to the naked
eye but your NVD can see it. This allows you to use your scope even in
total darkness. The IRI works like a flashlight and the distance you can
see with it will be limited. We do use the most powerful eye-safe
illuminator on the market. This allows our IRI to extend out to 100 yards
However, because of the power at a short distance the IRI may cover only
40-60% of the viewing area. 
There are many different variables that can effect the
distance that you can see with a Night Vision device. First, what are you
trying to see Are you looking for another boat on the water or are you
looking for a rabbit in the woods The larger the object the easier it is
too see. Plus, are you trying to see details (what we call recognition
range) or are you just trying to see if something is there or maybe you
will just see movement but won’t be able to 100% determine who or what it
is. This is called detection range. Second. Another variable is lighting
conditions. The more ambient light you have (starlight, moonlight,
infrared light) the better and further you will be able to see You can
always see further on a night where the moon and stars are out then if it
is cloudy and overcast. We typically state that you can tell the
difference between a male and a female or a dog and a deer at about 75 to
100 yards. However, if you were looking across an open field and there was
a half moon out you could see a barn or a house 500 yards away.
As you look
through a night vision device you may notice black spots on the screen. A
NVD is similar to a television screen and attracts dust and dirt.
Typically these spots can be cleaned. However, this may also be a spot in
the tube itself. This is normal. Most tubes will have some spots in them.
These black spots will not affect the performance or reliability of the
night vision device. 