Most people are familiar with the concept of night
vision. After all, it is seen in countless action and spy
movies. However, the truth is that night vision is more than
a fantastical concept; it is reality. And with goggles,
night scopes, binoculars and monoculars, it is possible to
see on a moonless, cloudless night. In fact, the technology
is so advanced that you can see a person standing more than
200 yards away. That’s twice the length of a football
field! The remarkable feat of human sight at night is
accomplished one of two ways: image enhancement or thermal
imaging.
Image enhancement is a night vision technique that
collects tiny amounts of light that may not be perceptible
to the human eye. These are the smallest glimmers of light,
sometimes even on the lower end of the infrared spectrum,
that are discovered by the device in use. The points of
light are than amplified by the device to a point that
allows the object or person to be seen easily.
The other way night vision works is by thermal imaging.
This is technology that works exclusively in the upper
portion of infrared light. Rather than gathering reflected
light, this is heat that is given off by objects or people.
This is known as thermal infrared, and it occupies the
largest amount of space as part of the infrared spectrum
(which is at the lower end of the light spectrum, below what
is detectible by the human eye). This means that there is a
great deal of wavelengths that can be detected by the proper
devices. Because thermal imaging works by putting the heat
coming from objects in visible form, it is to be expected
that some objects will appear clearer than others. Humans,
for example, emit more heat than a tree, and so a tree will
not be as clear.
Night vision products make excellent additions to any
surveillance collection, and they can be very helpful in
locating objects or people in dark places. You will pay in a
price range from under $300 to more than $15,000, depending
on features, accuracy, and purpose of the accessories you
choose to aid your night vision.
(c) 2005 Copyright www.spyassociates.com.
This article is about: Night Vision
This article was posted on September 30, 2005
