How Do Night Vision Equipment Work?
Night vision equipment refers to electronic-cum-optical devices which work by amplifying or intensifying whatever light there is in existence, rather than depending on a source of light built into them. They are sensitive to a wide spectrum of light, which ranges from visible to infrared.
Hence, when viewing something with a night vision device, you do not look through it. Instead, you are viewing an electronic image that is amplified on a phosphor screen. The light enters via an objective lens and then falls upon a photo cathode, which has a high energy charge via the power supply.
This charge of energy accelerates through a vacuum that exists in the intensifier and falls upon a phosphor screen, similar to a TV screen, which is the place where the image is focused. The image is magnified by the eyepiece.
The phosphor screen of a night vision device is green in color, since the human eye has the ability of differentiating more green shades compared to other phosphor colors.
Similar to cameras, night vision gadgets have a variety of image magnifications. The length at which a figure about the size of an adult human can be discerned clearly under normal night lighting conditions, such as star light and moon light, without any fog or haze, is dependent on the strength of the image intensifier, and the power of the objective lens.
Thermal Imaging Technology
In this technology, the upper part of the spectrum of infrared light is captured. This is given off as heat by objects, rather than being reflected as light. Warmer bodies, such as humans and animals, give off more of this light compared to colder objects such as buildings or trees.
Image Enhancement Technology
Here miniscule amounts of light are collected, which includes the lower part of the infrared light spectrum, which are in existence, but may not be perceptible to human eyes, which is them amplified to the extent that the image is easily visible to us.
These are very useful for night surveillance, home surveillance, home security, viewing animals or hunting them after dusk, keeping watch at night, stargazing, and watching comets or shooting stars.
Night vision technology was originally created to find enemy targets in the dark. The military still uses it extensively for targeting, surveillance, and navigation.
The police too use it for surveillance, as do nature enthusiasts and hunters. Many businesses install such equipment for monitoring purposes. Private investigators and detectives too find these gadgets useful in their line of their work.