Which is better: a Thermal Imager or a Night Vision Device? We will help you figure it out and after a couple of minutes of reading you will become a guru in this matter. Each of these technologies has its own strengths and benefits. Using them correctly, you can get the very “Wow” effect that we all count on when we buy a brand new device.
What are Night Vision Optics.
Night Vision Optics is a device that allows you to see at night. It comes in the form of glasses, binoculars, scope, monocular and camera. You say that the night is dark and how can some Night Vision Goggles turn it into day? This process is possible thanks to the photocathode, which converts light streams into electrons. Electrons increase their number in the microchannel plate by several thousand times and hit the phosphor-coated screen. Phosphorus is a phosphor, it glows when bombarded with electrons, that is, it emits photons of light. Streams of photons form an image on the screen of Night Vision Optics. In short, a Night Vision Device amplifies subtle light and allows us to see in the dark. Note that for the image to appear, you need light. When the sky is overcast and there is no light, NV Optics work thanks to infrared light illumination. We can’t see it, but Night Vision Equipment does.
Types of Night Vision Optics.
Analog Night Vision.
The whole light amplification process that we described above is inherent in analog or true Night Vision. The amount of light increases due to the electro-optical amplifier (EOP). Improving, image intensifier tubes received names for each of their new series. They began to be called generations (Gen) and assigned them numbers: Gen1…Gen3+. The older the generation, the stronger the increase. Generation determines the degree of illumination in which the NV Optics work, the target detection range, the service life and some additional features.
Generations of Night Vision Devices.
Gen1 is the most demanding for a large amount of light, it has a small detection distance of several tens of yards, an indistinct image with noise on the outer circle, and a very modest life. These devices will be suitable for solving everyday problems and entertainment.
Gen 2 is designed to operate at a distance of several hundred yards. Has a clear image with little marks on the outer contour. Popular with law enforcement agencies, police, hunters, rescuers, security.
Gen 2+ features excellent contrast and image clarity, with subtle inclusions. It operates in very low light and detects objects up to 600 yards away. Its service life has grown to 5000 hours. Optics with Gen 2+ are in demand in the army, police, rescue services, loved by hunters and homeowners. This is one of the best specimens in its class.
Gen3, 3+ are the pinnacle of technical thought and has the highest image quality. These generations are mainly used by the army and police. They are not afraid of side illumination, have an auto-strobe system and work without backlight in dense clouds. Detection range fluctuates around 980 yards depending on model and air clarity. It has a phenomenal lifespan of up to 15,000 hours.
The latest generations may not have a green picture, but black and white. The color is affected by the type of phosphorus used in the equipment.
Digital Night Vision.
In addition to the image intensifier tube, there is another type of light amplification – a digital sensor-CCD. It is used in NV Digital Device. The CCD sensor has many pixels that convert visible and IR light into electrons. The value of the charge of each electron is measured and in the form of an image, displayed on the LCD display. A different principle of operation allows some NV Digital device to operate during the day. They are appropriately marked and have warning labels.
What are Thermal Optics.
The Thermal Imager is based on the ability to register heat from surrounding surfaces and convert it into color flat images. Even in winter, in the bitter cold, in the presence of ice and snow, we can see a clear thermal impression of the landscape. The instrument records all temperatures above absolute zero -459.67°F. Ice and snow are much warmer than -459.67°F so there is no problem displaying them. As a rule, warmer places are marked in red, yellow; and colder places are in blue, green. All other temperatures have a color gradation depending on the readings. Thus, we can conclude that thermal imaging optics depends on temperature readings and is completely indifferent to lighting.
Types of Thermal Optics.
Thermal Imaging Optics are represented by a wide range of products. Among them you can find cameras, monocular, binoculars, sights. Thermal Imagers are divided according to the scope of use: household, industrial, research, medical, tactical, construction, fire, security, marine, astronomical.
In addition, there is a division based on the principle of mobility. They are large stationary and compact portable. Stationary industrial we will not explore in this article. Let’s pay attention to mobile versions of Thermal Imaging Optics and compare it with Night Vision.
Difference.
Illumination.
As we said above, the main difference is the use of lighting. Thermal Imagers do not need it, and Night Vision cannot work without it. Thermal technology can work day and night, but NV cannot be used during the day. In addition, Night Vision should be protected, even at night, from bright light sources and side illumination. Note that some models of Digital Night Vision, when using special filters, can work during the day. But, the image quality will be worse than its analog version.
We would like to draw your attention to the fact that the TV scanner marks the traces of warm bodies that have already left their place. For example, he will see traces of the animal lying down for a certain time, when it is no longer there. This fact is used not only by hunters, but also by rescuers when looking for missing people. In addition, fresh blood has a higher temperature than the environment, so even in complete darkness it is possible to follow the blood trail.
Difficult weather conditions.
Rain, fog, snow, smoke, and water will affect the two technologies differently. The fact is that any saturation of the atmosphere with particles, such as water, snow crystals or smoke particles, will cause the effect of partial absorption and reflection of the light flux. If the rain is dense enough, then the Night Vision Optics will produce noise on the screen, behind which it is impossible to see anything. It is better to postpone the use of Night Vision Devices until good weather, when the atmosphere is sufficiently transparent.
Note that difficult weather conditions also affect the operation of IR Equipment, but to a much lesser extent. Light, normal rain will not be a serious hindrance to observation. This applies to snow, fog and smoke. Therefore, if you need to detect a target during precipitation, then a Thermal Imager will help you.
Barriers.
There are options when the IR scanner does not cope. He does not see through glass, mirror, foil and waterfall jet.
Night Vision Optics do not see people and animals if they mimic the colors of the area. The Thermal Imager does not care if there is masking or not. If the object has a different temperature than the background, it will be detected.
TV Optics can easily detect a target in grass or foliage, behind openwork fences, among thin partitions. But all this can interfere with the movement of the operator. He simply will not see small branches and bushes. NV, on the contrary, will give a very realistic picture, with all the small details and allow you to freely navigate the terrain.
Differences in images.
Devices with NV give a spatial picture that is almost familiar to our vision. Depending on the color of the phosphor, the picture may be greenish or black and white. You quickly get used to it and there are no special problems when You quickly get used to it and there are no special problems when movement. Among the latest innovations, it is worth paying attention to the «Colorpath» technology. It converts a monochrome image into color, almost the same as we see during the day.
Unlike Night Vision, Thermal Imaging Devices give a flat image with colored spots, without the usual shadows and three-dimensional space. It is impossible to correctly estimate the distances between objects and their dimensions. Some reading skill is required.
When viewed through a Thermal Imager, it is clear that is a person, but it is impossible to identify him. Small details are not visible on the TV Screen. From this point of view, NV is a better acquisition. It allows you to consider the details, whether it is the antlers of a deer or the features of the figure and face of a person.
To summarize all the information, the conclusion suggests itself: TV is great for target detection, especially in bad weather and difficult terrain, and NV is indispensable for target recognition and for correct orientation. Both of these technologies are almost equal in terms of resistance to weapon recoil and temperature extremes. As for the recognition range, good Night Vision Optics are still in the lead. In terms of price, thermal imagers can be a bit more expensive, but not in all categories. The latest generations of Night Vision are quite expensive. However, the offer in both technologies is so diverse that everyone can choose according to their taste and budget.
