Night Vision

Night Vision is the general term for the technology of image intensification. An Image Intensifier Tube (IIT) is incorporated within a Night Vision Device (NVD), providing an operator the capability to amplify the available ambient light. This amplification subsequently allows the Night Vision Device to operate in low-light.

Image Intensification operates by amplifying the available light to achieve better vision. An objective lens focuses available light (photons) on the photocathode of an Image Intensification Tube. The light energy causes electrons to be released from the cathode which are accelerated by an electric field to increase their speed (energy level).

Electrons enter holes in a microchannel plate and bounce off the internal specially-coated walls which generate more electrons as the electrons bounce through, thus creating a denser 'cloud' of electrons, representing an intensified version of the original image. The final stage of the image intensification involves electrons hitting a phosphor screen.

The energy of the electrons enables the phosphor screen to glow. The visual light exhibits the desired image to the user via the eyepice of the Night Vision Device or to an attached photographic camera or video device.

A P43 green phosphor is used in these applications as the human eye can differentiate more shades of green than any other colour, allowing for greater differentiation of objects. Recently however, Night Vision Devices have been supplied with P45 B&W Image Intensiier Tubes which ahve become popular in recent times...  end-users stating that the B&W image results in reduced eye-fatigue.

There is a large array of Image Intensifier Tubes available for Night Vision Devices (NVD's) and Night Vision Goggels (NVG's), from FOM630 up to FOM2300… see  Tube Specifications for more information on the range of Tubes.

Night Vision typically falls into three categories, that is, Night Vision Devices, Night Vision Modules and Night Vision Goggles.

Night Vision Devices are also commonly referred to as NVD’s, Night Vision Monoculars & Night Vision Scopes.

Examples of Night Vision configuration variations include, but aren’t limited to:
- Night Vision Devices (NVD’s)

-  Night Vision Goggles (NVG's)

- Night Vision Modules (NVM's)

The variety of Night Vision kit utilise a myriad of Image Intensifier Tubes (IIT), which exhibit various levels of resolution, sensitivity & signal-to noise, see:  www.militaryandlaw.com.au/tube_specifications.html

Night Vision Devices can be operated as handheld, head-mounted or attached to cameras & camcorders for image gathering.

Night Vision Goggles are utilised for hands-free, low-light observation such as whilst driving or being utilised in an OP (Observation Point).

Night Vision Modules are used specifically for low-light, extremely high resolution image gathering, whilst utilising the dSLR body's native objective lens.

Rife within the Night Vision industry is Image Intensified Tube substitution. This is where a piece of kit is procured, such as a Night Vision Monocular, however the purchaser is unaware of which Image Intensifier Tube has been utilised in the kit, see:  www.militaryandlaw.com.au/tube_substitution.html.