Gen. 2+ Night vision devices are the most common high-quality devices in Europe since they offer extremely good quality picture and resolution.
Dipol D209 Night Vision Binoculars
The useful range of Gen. 2+ night vision devices is mostly far beyond 200 meters, if there is just a small amount of light. If there are just a few stars visible, mostly this is enough to see the observed object enough clearly. In complete darkness, we would still recommend using a high-quality infrared illuminator, which works on a wavelength of 850-875nm. This wavelength can't be noticed by animals, even if the infrared beam shines directly in their direction.
For the 2+ Generation, many different photocathodes are available, from the most basic ones to technologically advanced ones. The difference is in the resolution, which is measured in lp/mm, photosensitivity - which is measured in μA/lm and in Gain (light amplification). The latest photocathodes are already very near the generation 3 photocathodes – XR-5 and ECHO for example. Through all photocathodes, the image is black and green, but the technological advance ones are available also with white phosphor, which makes the image black and white.
High-quality manufacturers offer also the auto-gating feature, which automatically reduces the voltage when a bright source of light appears in the front of the optic, to protect the image-intensifier tube.
Be sure you don't expose the 2+ generation analog night vision devices to sunlight because it can damage the image-intensifier tube!