Company News
How Night Vision Devices Work Time:2015/7/20
Without going into too much scientific detail, the basic principle of night vision devices is that incoming photons strike a photoelectric plate. A photoelectric plate is one which reacts to being struck by photons by releasing a number of charged particles, electrons, for each photon that strikes it.

These electrons are then accelerated through a photomultiplier, which produces even more electrons by using a very high voltage to propel them down a tube. The electrons then strike a phosphor screen, which reacts to them by creating pools of light which is visible to the human eye.

While the above is reasonably accurate, it is necessarily a slight simplification of the processes involved. The most important point to remember is that the most common devices merely amplify the existing light. Consequently, the image is slightly blurry and low resolution, but perfectly adequate for many low level hunting applications.

There are several generations of device, each using slightly different principles to achieve the same result (with differing degrees of success). Some are more technologically advanced than others, and consequently come with different price tags attached to them.

So called second generation devices work by taking the electrons and forcing them through a device known as a micro channel plate (MCP) which multiples them, and produces a much larger stream of electrons which are then propelled towards the phosphor screen as before.

The result is a better image, which is somewhat less fuzzy, and can be viewed whilst moving in reasonable conditions. They also cost about $1,000 more, but well worth it for the hardened night hunter.

There are also third and fourth generation models used in military and police environments which use chemical layers over the phosphor screen to achieve a brighter image with better contrast.

All of the above rely on some light to work effectively - unlike passive scopes, however, they only need a very small amount of light, and can amplify it by up to a thousand times. They will still not work in complete darkness, however, but this is a very rare situation to be in.

For operation in complete darkness, or in cases where extremely high image clarity is a requirement (emergency, police, military and surveillance), an infra red augmented device will be needed.