What do you mean by night vision? Night vision means the ability to see things in low
light conditions, despite whether by natural or technological strategies. Night vision is made
possible with two methods sufficient spectral range and sufficient intensity range.
Night vision is generally used by military and in home video cameras, traffic cameras etc.
The types of night vision technologies used are
Low light imaging
Thermal imaging
Near infrared illumination
Color Night vision
Low light imaging
Low light imaging technology is used to improve visibility in faintly lit conditions. In this
method, we use a device called image intensifier to amplify the available light. The dim light
available in the environment is focused through a lens onto a photocathode of image intensifier.
The image intensifier is a vacuum- tube based system, it converts iow light from the image to
visible light by this method object in the dark can be seen by camera and eye.
Advantages
High low light sensitivity
Good resolution
Low power and low cost
Disadvantages:
this technology need some light without any small light this technology does not work .
Inferior daytime performance when compared to daylight-only methods.
Thermal imaging
Thermal imaging is a technique used to improve the visibility of objects in the dark. This
is done by detecting infrared radiation emitted from the body and thus creating a image based on
the infrared radiation. Here we use a thermal sensor which is basically a heat sensor which hass
an ability of detecting small changes in the temperature. This device detects and collect the IR
radiation from the object and creates an electronic image based on the information collected by
the thermal sensor.
Near Infrared illumination
Near infrared technologies work on the principle of coupling imaging intensification with an active source of illumination in the near infrared (NIR) band.. This is an inexpensive method used for night vision
Color Night Vision
Color night vision is referring to the removal of the camera’s low light operation as in this technology the minimum light needed to keep the camera’s video in color mode is reduced to lower light levels.
When there is no light then there is no ‘color night vision’, then the camera is pushed to true IR black and white image. so in this technology, it does not create a colour video in full darkness, it provides color images in most scenarios.
