Determining the difference between night vision devices
is not an easy task.
What is it / how does it work?
Night vision allows the user to see objects and surroundings
even under the darkest conditions without additional illumination.
The heart of night vision is an image intensifier tube
(IIT) which amplifies the ambient light by many thousands
a times. In addition to visible light, this tube is sensitive
to infrared radiation. That means that you can use invisible
infrared illuminator to add luminescence to the objects.
The unit collects light from all possible sources (stars,
moon, distant urban illumination, built-in or add-on infrared
flashlight, etc.) and projects an image on the screen.
Do's and Do Not's
· NEVER take the unit apart. This device
contains high voltage, which may be hazardous to your
· NEVER expose the opened objective lens
of a unit to daylight or bright artificial light. (Note:
1st generation devices remain active for a
few minutes after switching off). You can turn the unit
on during the day, but the caps must cover objective lenses.
a tiny hole in the lens caps to provide enough light for
· NEVER aim active units at intense light
sources (i.e. lights, headlamp, campfires, the moon, etc.)
It will not make you blind like in the movies,
but it will harm the unit.
· NEVER reverse the polarity of a battery
· NEVER connect the unit to external power
· ALWAYS keep the objective lenses covered
when not in use
· ALWAYS store in a warm dry place when
not in use
· ALWAYS remove battery when not in use
for a long period of time.
Glossary of terms:
Image Intensifier Tubes:
Collects and amplifies light, which is then displayed
on the display.
Binoculars vs. Monoculars:
A night vision monocular is designed for use with one
eye and contains one image intensifier tube. A night vision
binocular is designed for use with both eyes and contains
two image intensifier tubes. The hybrid of binocular and
monocular is called bi-ocular. It splits the image projected
by a single tube into two channels. This construction
is as convenient as an ordinary binocular, but twice less
expensive. However, it doesn't provide stereo vision and
twice less brightness than a normal binocular.
The quality of different night vision systems is graded
by generations. Simply put, Gen 1 was developed long ago,
but is still in production because its performance is
sufficient for the consumer applications and the cost
is affordable. Gen 2 came next considerably increasing
the quality of the image intensifier tube. Gen 3 followed
with an even better image. As the technical answer to
American Gen. 3 design, the European companies decided
to develop the Gen 2 technology. Gen 2+ or Supergen, can
be consistently compared on par with Gen 3.
I/R illuminators emit light with wavelengths of about
800 nanometers. This range is perfectly accepted by night
vision equipment of all generations. At the present time,
all night vision have built-in infrared diodes. Designated
hand-held or stationary illuminators are also available.
This equipment increases the night vision functionality
allowing it to work even in total darkness. Normally illuminators
are completely eye safe, but with power increasing and
stepping from infrared LED to infrared laser the devices
may become not eye safe and potentially hazardous. This
parameter is one of the most important to know when you
buy the illuminator. I/R emitting devices are almost invisible
from the opposite side unless your probable rival also
has night vision equipment. This is why the information
about whether I/R is on or off is very important for combatant
This device is very similar to the previous one, but
it emits a very narrow beam. The task of the aimer is
not to light the terrain but to spot the target only.
Usually aimers are used with different weapons.
Measured in line pairs per millimeter (lp/mm), this is
the clarity or quality of the image seen on the screen.
The higher the number, the better the image quality is.
However, buyer beware, these numbers are often inflated
by some companies because it is impossible for the average
customer to test this parameter without special, very
expensive equipment available only at factories.
Magnification in Night Vision:
Higher is not always better, and this is one of the cases.
Higher magnification means lower brightness and poorer
visibility. Normally night vision magnification is 1x-2x.
Good Gen. 2+ and 3 devices can have 4x-5x magnification.
Higher magnifications are useless unless these are very
professional units with huge and heavy optics, which cost
thousands of dollars itself.