What are the key points to consider when buying infrared night vision equipment?
1. Booster tube: it is several generations. When you buy, be sure to confirm to the merchant. Because the night vision device packaging and instructions are generally not labeled with a few generations of booster tube. Of course, if you want to buy 2 or 3 generations of night vision devices, it is best to buy a clearly marked is a few generations of booster tube night vision devices, so as to avoid infringement of your rights and interests. Currently on the market, such as the Russian RHO night vision device in the product packaging and the machine are labeled with the use of the first generation of booster tube.
2. Lens: look at the lens caliber and magnification. In the case of not considering the volume, of course, the bigger the better. The same tube situation, in principle, the larger the caliber, the farther the observation distance, the clearer the image.
3. Image enhancement technology: generally with this technology night vision device, under the same conditions the image brightness will be better and clearer.
4. Infrared emitter: this performance is good or bad, but also directly affects the image quality.
5. Resolution: the resolution of the lens is very important, the higher the resolution the clearer the image displayed.
As for the night vision device nominal observation distance, identification distance. Because there is no formal standard, each said differently. In fact, there is no reference significance. Generally speaking: 1 generation of the distance in 100-250 meters, 2 generations of the distance in 200-350 meters, 3 generations of the distance in 300-500 meters, able to see objects. Specifically also subject to the size of the lens quality, image processing technology, infrared emitters, the impact of the resolution and decide.
The basic principle of night vision
In order to understand the principle of night vision, it is necessary to have an understanding of the principle of light. The amount of energy in a light wave is related to its wavelength: the shorter the wavelength, the higher the energy. In visible light, violet light has the highest energy, while red light has the lowest. Adjacent to the visible light spectrum is the infrared spectrum. Infrared light is divided into three categories:
Near infrared (near IR) - Near infrared is adjacent to visible light and has a wavelength range of 0.7-1.3 microns (1 micron equals one millionth of a meter).
Mid-infrared (mid-IR) - Mid-infrared has a wavelength range of 1.3-3 microns. Near infrared and mid infrared are used in a variety of electronic devices, such as remote controls.
Thermal Infrared (Thermal IR) - Thermal infrared occupies the largest portion of the infrared spectrum and has a wavelength range of 3-30 microns.
The main difference between thermal infrared and the other two types of infrared is that thermal infrared is emitted by an object rather than reflected off of it. An object is able to emit infrared light because its atoms have changed in some way.
