Answers to the Basic Knowledge of Night Vision Devices
1. When will night vision products be used?
Used for leisure and entertainment purposes, such as camping, traveling, fishing, boating, or natural observation. Other uses include surveillance, search and rescue, and security purposes.
2. What are the differences between different generations of night vision products?
The main difference lies in the advancement of enhancer technology. The first generation uses an enhancement tube to enhance the brightness of the surrounding environment, which can accelerate the impact of electron flow on the phosphorus surface, similar to the principle of a television screen. The second generation device has added a micro frequency disk to increase the number of electrons colliding with the phosphorus surface, thereby enhancing brightness. The third generation device has added a gallium arsenic photocathode, which produces a greater number of photoelectrons than the second generation. Both the second and third generations have made significant progress in improving brightness, but their prices are relatively expensive, which has deterred most customers. The quality of the first generation is good, and its brightening effect can also meet the needs of most ordinary users and many professional users, so it has a relatively promising market.
3. How does a night vision system work?
The night vision product focuses the light on the image intensifier through the eyepiece to collect and enhance the existing light. Inside the intensifier, a photocathode will be "activated" by the light, and the photon energy will be converted into electrons. These electrons will be accelerated through an electrostatic area located inside the intensifier, and then hit the phosphorus surface screen (just like a green TV screen), forming a visible image. Through the acceleration of electrons, the brightness and image clarity have been enhanced.
4. What is the optimal range of a night vision instrument?
It varies within a range of approximately 10 to 400 feet* The distance of the large field of view depends on the usage environment, such as cloudy weather, foggy or rainy days, which can shorten the range of the night vision instrument. Infrared emitters can improve range, especially when used in enclosed areas such as warehouses, caves, etc.
5. Why doesn't the night vision system have an amplification function?
The larger the image, the more light is lost.
6. Why is it focused at the front (target lens) and eyepiece (eyepiece)?
The brief answer is that you are not looking through night vision devices, in fact, what you see is the phosphorescent screen at the bottom of the tube. The target mirror focuses the image in front of the enhancement tube, which converts the image into an electron stream and then re images at the bottom of the tube. To see a clear image, it is necessary to focus the eyes on the imaging area at the bottom of the enhancement tube. Everyone's eye vision is different, so eye focus is also very important. Firstly, focus your gaze and then shift to the target mirror to ensure a clear image is visible. Additionally, you need to use each prism several times to obtain a clear image.
7. How should I use a night vision device in low light or completely dark places?
All night vision devices require existing light to function, and using an infrared generator, it is possible to see bright images in low light and completely dark environments.
8. Since night vision devices can detect infrared light, can they detect heat?
A night vision device is an optical amplifier that can operate in the "almost visible" light range, typically in the range of 750-850 nanometers. It cannot measure heat because the thermal frequency is much lower than the spectral frequency, and thermal imaging technology is also required.
9. What type of light source is harmful to night vision equipment?
Night vision equipment is designed for use in dark environments, and if used during the day or in very bright environments, it can harm or even damage the equipment. Please remember: If you direct your night vision device to strong direct light, such as projectors, car headlights, strong flashlight light, etc., it may damage your night vision device. Nevertheless, night vision devices all have devices to protect themselves from such damage, mostly by simply closing the overload circuit, while others use more precise equipment and spectroscopic devices for protection.
