Available light (energy) is collected by the objective lens and
focused on the image intensifier.
Inside the intensifier a photocathode is "excited" by the light and
converts the energy into electrons.
The electrons accelerate across an electrostatic field inside the
intensifier and strike a phosphor screen (like a monochrome TV screen)
which emits an image that you can see. This acceleration of electrons
provides gain and enhances the image.
Types of Night Vision
Generation 1 - Does not require an active infrared
light source. Instead it amplifies available ambient light.
Advanced Night Vision - Utilizes fiber optic
bundles to eliminate distortion and noise resulting in a
high-resolution, high-contrast premium image. Superior contrast allows
you to see dark subjects against darker backgrounds. Lower distortion
renders a flatter, less rounded image with crisper details.
Digital Night Vision - Utilising a CCD image sensor
& a number of LED infrared illuminators, digital night vision doesn't
have the distortion around the edges nor black spots that traditional
night vision has.
Night Vision Binocular - Two complete sets of
optics and image intensifiers that are connected together and share a
common power supply.
Night Vision Monocular - A Night Vision device for
use with one eye.