How Night Vision Works

Night Vision is an imaging technology designed to improve visibility in minimal light or the absence of it. This imaging technology utilizes the upper or lower portion of the light spectrum to create a clearer and more detailed picture of the target.

Principles behind Night Vision Technology

Night vision technology geared for image enhancement uses the infrared spectrum's lower portion and magnified minute quantities of light in order to improve the image quality. Night vision thermal imaging on the other hand captures the infrared spectrum's upper portion which is composed of emitted heat to produce a thermal image of the target.

In essence, night vision devices utilize the portion of the light spectrum that is not visible to the human eye in order to create a clearer picture. Contrary to the visible portion which depends wholly on the reflection of light, garnering image data from the infrared spectrum means that the night vision device makes use of the target's emitted thermal energy. This emission of thermal energy is caused by the emission of photon particles by the target because of atomic energy release after excitation.

Components of a Night Vision Device

A night vision device uses a special lens for focusing of all the infrared light emitted by the target and other objects in view. A thermogram temperature pattern is created by the phased array that scans the focused infrared light. This thermogram temperature pattern is converted to electrical impulses and sent to the unit's computers for processing and translation into an image the user can understand.

Thermal Imaging Device Types

Thermal devices can either be un-cooled or cryogenically cooled. Although cryogenically cooled thermal imaging devices produce a much better picture than an un-cooled thermal device (because of its greater temperature scanning range), these devices are a lot more expensive and prone to damage. Moreover, the un-cooled thermal imaging device operates at room temperature, is faster and is a lot quieter to operate.

Image Enhancement Night Vision Devices

Image enhancement night vision devices make use of an image intensifier tube that gathers and magnifies visible and infrared light. Image enhancement devices make use of an objective or conventional lens to collect light and infrared. These collected photon particles are passed through the image intensifier tube powered by batteries. Inside, a photocathode is utilized to convert the photons into electrons. The number of electrons is multiplied in the order of thousands by using an MCP or micro channel plate. A phosphor-coated screen, located at the image intensifier's end, catches the electrons and emits photons upon electron impact. These phosphors produce the characteristic green color of night vision images which are viewed through the ocular lens.

Uses of Night Vision Technology

Night vision technology has been around since World War II. Today, these devices are still being used in the military as well as by law enforcements agencies, entertainment companies, surveillance and security systems, and wildlife studies. They can come in the form of goggles, scopes or cameras depending on the purpose.