Night Vision Equipments | Night Vision Devices
This page describes Night Vision basics, Night vision equipments or night vision devices with applications. The equipments/devices covered are night vision goggles, night vision binocular, night vision monocular, night vision scope etc.
What is Night Vision ?
The ability to see in the low light conditions is known as night vision. This is not possible with naked eye by human beings and hence require night vision devices to see in low light conditions.
As we know ability to see in low light conditions is governed by two basic requirements viz. sufficient spectral range and sufficient intensity range. These values are found low in human beings and hence they do not see in the low light conditions. Use of technology to enhance both of these parameters make is possible to see in low light conditions.
There are two basic approaches to night vision which include image intensification (i.e. enhancement)
and thermal imaging.
Image intensification works on the principle of collecting small quanta of light reflected off the target
scene to be viewed in visible amd near IR bands of electromagnetic spectrum in low light conditions.
Collected photons are amplified through the processes of photon electron conversion, electron multiplication and
electron-photon conversion. These processes are carried out in image intensifier tube.
Thermal imaging works on the principle of detecting temperature differences between the objects in the foreground
and those in the background.It works based on the fact that all the objects above absolute zero temperature emit IR
energy. The hotter the body the higher the magnitude of IR energy emitted by the object and lower the
wavelength of peak emission.
Night Vision Equipments | Night Vision Devices
Night vision equipments or devices are used in wide range of applications including military, law enforcement,
hunting, surveillance, navigation, security, wild life observation and so on.
The night vision devices are also used by private detectives, fire fighters, hunters and nature enthusiasts.
They are mainly made using image intensifier tubes. The popular among them are listed below.
night vision goggles: It is an opto-electronic device which allows images to be produced in total darkness.
night vision cameras These cameras improve video images in low light conditions and hence they provide
enhanced security. They are used extensively for surveillance and security applications especially for around the clock
surveillance both in indoors and outdoors. With the help of IR illumination, these cameras can be used effectively in
near total dark conditions. These cameras are also known as 24 x 7 cameras due to their 24 hours operation.
They are available in two shapes viz. dome and bullet.
night vision binocular: You can use both eyes to view far-away image very near
using it. One can have 3D image which has many benefits to the users.
It is like having two mini-telescopes for each eye.
night vision monocular: It is just one side barrel of a pair of binoculars. It is also known as
mini telescope or tiny spotting scope.
night vision scope: It is also an electro-optical device which is used to provide
visible image in the low light conditions usually at night. It uses visible and infrared
energy for its operation. They can only be used at night and not during the day.
This is the only disadvantage of the night vision scope.
Other optical test and measurement equipments
Optical Spectrum Analyzer
Optical Time Domain Reflectometer
Optical Wavelength Meter
Densitometer
Spectrophotometer
Optical Thickness Guage