Heat finds – night vision binds
The state of North Rhine-Westphalia has based its legislation on the guiding principle “Heat finds, night vision binds”. In the state, only night vision devices and night vision attachments based on tubes are permitted for firing that amplify the available residual light. However, thermal imaging attachments as well as digital night vision devices are prohibited for firing. We have summarized more information about this in a separate text.
General Info
For night vision technology based on image intensifier tubes, the weather of the previous days is irrelevant. However, for the image quality of a thermal imager this is crucial! The images shown above were taken on the evening of October 30, 2021 – shortly after each other. On this and also the previous days, the sky was clear (14°C during the day, 7°C at night). Ideal conditions for thermal imaging.
Possible applications of thermal imaging
Thermal imaging has proven itself for the rapid detection of game, sometimes at several hundred meters, because heat signatures are clearly visible on the screen. This means that nothing remains hidden in the hunting area – regardless of stalking or hide hunting. Even in adverse weather conditions, heat signatures can still be perceived despite considerable loss of quality.
A major problem with thermal imaging is “bad weather”. (crossover or quadriga effect). Owners of thermal imaging technology know the phenomenon especially in autumn and winter. If the weather has been cloudy for several days, often in combination with low temperatures, it becomes more and more difficult to recognize the landscape. It is also very difficult to estimate the distance. Another big problem then is a bullet trap that cannot be adequately recognized.
A major problem with thermal imaging is “bad weather”. (crossover or quadriga effect). Owners of thermal imaging technology know the phenomenon especially in autumn and winter. If the weather has been cloudy for several days, often in combination with low temperatures, it becomes more and more difficult to recognize the landscape. It is also very difficult to estimate the distance. Another big problem then is a bullet trap that cannot be adequately recognized.
On the left picture you can see a landscape with roe deer after it was very cold for several days and the sun was not shining. On the right the same detail only one day later. However, during the day the sun came out again and the landscape could “warm up”.
If you look closely, you can see the tree on the left in the left picture. (Unedited original images: Vox sensor 400×300, 35-mm lens. Camera settings identical.)
Likewise, obstacles in the “shot path” are difficult, if not impossible, to see.
Even branches with a diameter of 1.6 (!) cm, as in this shot, are hardly discernible.
Two cows, distance approx. 100 meters, shot with a spotter, basic magnification: 2.3 x, sensor: 400 x 300, pitch 17 mm
In combination with primary optics, such as a riflescope, considerable quality losses are to be expected. Especially when viewing an LCD or OLED screen, like thermal imaging or digital devices have, the images are displayed extremely pixelated in combination with primary optics. The higher the magnification of the primary optics, the stronger this effect becomes.
The same situation, recorded with a thermal imaging attachment, S3ensor: 400 x 300, pitch 17 µm
When used with a rifle, depending on the model, there may be an offset of the image when panning along with the game. Image interruption due to calibration may also be problematic.
In combination with primary optics, such as a riflescope, considerable quality losses are to be expected. Especially when viewing an LCD or OLED screen, like thermal imaging or digital devices have, the images are displayed extremely pixelated in combination with primary optics. The higher the magnification of the primary optics, the stronger this effect becomes.
When used with a rifle, depending on the model, there may be an offset of the image when panning along with the game. Image interruption due to calibration may also be problematic.
Possible uses of night vision technology
Night vision technology does not provide a calculated image, but a real-time image with extremely high detail. The image corresponds to the daytime image, except that it is displayed in green, yellow or black and white. This is the only way to ensure that the target can be seen even at long distances. Especially when used with primary optics, the loss of quality is much less significant, as the following pictures clearly illustrate.
Night vision technology has already proven itself for decades. In addition to the excellent image display, the mature technology impresses with extremely low power consumption and has no start-up time delay or calibration interruption compared to thermal imaging technology.
Night vision technology does not provide a calculated image, but a real-time image with extremely high detail. The image corresponds to the daytime image, except that it is displayed in green, yellow or black and white. This is the only way to ensure that the target can be seen even at long distances. Especially when used with primary optics, the loss of quality is much less significant, as the following pictures clearly illustrate.
Night vision technology has already proven itself for decades. In addition to the excellent image display, the mature technology impresses with extremely low power consumption and has no start-up time delay or calibration interruption compared to thermal imaging technology.
The disadvantage is that game is not detected as quickly as with a thermal imaging camera and there is a loss of quality in fog.
By the way: night vision technology also helps to reliably detect fresh game. This is because, compared to thermal technology, the stripes of the freshets are clearly visible with night vision technology. With thermal cameras, individual freshets are difficult to approach because the typical stripes are not visible due to the lack of temperature differences.
The disadvantage is that game is not detected as quickly as with a thermal imaging camera and there is a loss of quality in fog.
By the way: night vision technology also helps to reliably detect fresh game. This is because, compared to thermal technology, the stripes of the freshets are clearly visible with night vision technology. With thermal cameras, individual freshets are difficult to approach because the typical stripes are not visible due to the lack of temperature differences.
Both pictures were taken with observation devices called “spotters”. Here the difference of the two technologies becomes clearly visible. Particularly when addressing game, it is details that make the difference. Image intensifier tubes optimized for hunting produce a high-resolution image that clearly shows whether, for example, a defector, a sow or a boar is in the viewfinder. Important details such as the milk bar of a sow can also be clearly seen. Classic night vision devices also show their strengths with red deer – because the cold horns of a trophy bearer, which are not supplied with blood, are often hidden from thermal imaging cameras or can only be seen in the bast. In addition, the increased distance makes accurate targeting via heat signature nearly impossible.
Thermal image, basic magnification: 2.3 x, sensor: 400 x 300, pitch: 17 µm
Both pictures were taken with observation devices called “spotters”. Here the difference of the two technologies becomes clearly visible. Particularly when addressing game, it is details that make the difference. Image intensifier tubes optimized for hunting produce a high-resolution image that clearly shows whether, for example, a defector, a sow or a boar is in the viewfinder.
Night vision device, 5x magnification, lens diameter: 55mm
Important details such as the milk bar of a sow can also be clearly seen. Classic night vision devices also show their strengths with red deer – because the cold horns of a trophy bearer, which are not supplied with blood, are often hidden from thermal imaging cameras or can only be seen in the bast. In addition, the increased distance makes accurate targeting via heat signature nearly impossible.
These are some of the reasons why the state of North Rhine-Westphalia has not approved thermal imaging and digital night vision technology for shooting and their use is prohibited.