Little knowledge of night vision devices
How do night vision goggles work?
---Night vision products focus the light on the image intensifier through the eyepiece to collect and intensify the existing light. Inside the intensifier, a photocathode will be "activated" by light and convert photon energy into electrons. These electrons pass through An electrostatic field inside the intensifier is accelerated and hits the phosphor surface screen (like a green TV screen), creating an image visible to the human eye. Through the acceleration of electrons, the brightness and image clarity are enhanced.
What is the optimal range for night vision goggles?
---Approximately within the range of 10-400 feet. The maximum viewing distance depends on the use environment, such as cloudy weather, fog or rain, etc., will shorten the range of the night vision device. Infrared emitters can increase the range, especially when used in enclosed areas like warehouses, caves, etc. Another point is that even the night vision devices of the same generation have very different observation distances, which are related to the quality of the image intensifier tube, internal optical devices, and data processing. For example, Orfa ORPHA CS2 5X50, the world’s best-selling single-tube night vision device for three consecutive years, has an observation distance far beyond other night vision devices of the same price. Its price is only US$200, but its observation distance can reach more than 200 meters. However, night vision devices of the same price can generally only observe about 100 meters.
Why focus both at the front (objective) and at the eye piece (eyepiece)?
---The short answer is that you are not looking through the night vision device, you are actually seeing the phosphor screen at the bottom of the tube. The objective lens focuses the image in front of the intensifier tube, which converts the image into a stream of electrons, which are then reimaged at the bottom of the tube. To see a clear image, you need to focus your eye on the bottom of the intensifier tube where the image is formed. Everyone's eye vision is different, so eye focus is also very important. Focus the line of sight first, and then transfer to the objective mirror to ensure a clear image. Also, you'll need several shots of each prism to get the sharpest image.
