Is our night vision as perfect as of nocturnal animals? The answer is no, but this is not a problem but a challenge for the modern world. This is the reason why night vision devices (NVD) and thermal imagers were created. Devices of this type expand our capabilities and give us an advantage over animals when hunting.
What is night vision? During the day, we see objects because sunlight falls on the surface of things, scatters, and gets caught by the eye’s retina. At night, there is a weak background infrared radiation with a wavelength of less than one km. To view the ambiance at night, it is necessary to receive this background radiation, amplify and transform it into a visible image. This is what some devices are specialized in.
First of all, we need to view a thermal imager. It does not depend on external lighting, unlike NVD. All subjects, whose temperature is higher than the temperature of absolute zero, emit electromagnetic radiation captured by the device. It reproduces an image based on the amount of heat that it could catch. The structure of a thermal imager is very similar to the design of NVD, but its sensors are sensitive precisely to thermal radiation. The matrix of the device consists of a large number of bolometers; their task is to distinguish any temperature changes. Then the signal is converted into an image on the screen. Optics for thermal imagers are not made of ordinary glass but of germanium, chalcogenide glass, etc., which do not transmit visible light and focus infrared radiation well. Thermal imagers include:
2) thermal imaging aim;
Theoretically, the term of validity of thermal imagers is unlimited, but like any technique, it can own some problems-the optical part may have non-working areas of the matrix.
Other devices – NVD work in low light; in the dark, they need IR illumination; everything can be an obstacle: snow, rain, etc. They are based on an electro-optical converter consisting of a photosensitive cathode and a phosphor anode with high voltage applied. The collected light knocks out electrons from the cathode. It directs them to the anode, acquiring additional energy during acceleration. As a result, the original image is obtained on the phosphor. Today, there are many types of NVD types: 1) monoculars; 2) binoculars: 3) glasses; 4) aims. Among them are the digital analogs of a video camera. The working life of the NVD is approximately the same; for the first generation, for instance, it is 3 thousand hours.
Hunting is not the safest activity, and you should not save on health. Therefore, a thermal imager can help, but you can purchase a 2+ or 3 generation image intensifier night aim for the price of an excellent thermal imaging sight. For most night hunts, even a 1st generation image intensifier is well suited for visibility at 150 m. An experienced hunter will be convenient a thermal imager, where only the contours of the animal are indicated, and the more expensive is an aim, the more detailed and contrasted it can be seen on the device.
After reading the article, we can conclude that these devices are entirely different by purpose, capabilities, and price. The most practical option for hunting is a combination of these devices.