What is the difference between night vision devices and thermal imagers?
3 Answers
The differences between night vision devices and thermal imagers are as follows: 1. Different imaging effects: (1) Night vision devices and ordinary infrared thermal imagers provide completely different observation experiences. This is because ordinary night vision devices directly observe the target through the lens, so the field of view is similar to that seen through a telescope lens, with the image appearing green. If the clarity is sufficient, it is possible to identify who the person is and see their facial features clearly. (2) Infrared night vision thermal imagers display the image on an internal LCD screen rather than directly observing the target. The imaging of an infrared night vision thermal imager is based on temperature distribution, with higher temperatures appearing brighter and lower temperatures appearing darker. Its main purpose is to detect targets and identify their categories, such as whether the target is a person, animal, etc. 2. Different influences of light factors: (1) Second-generation night vision devices are significantly affected by environmental conditions due to their imaging principles, especially light. When the light dims, the observation distance shortens. In complete darkness, an auxiliary infrared light source is required, which generally has a maximum range of only 100 meters. They are also sensitive to strong light, even though many traditional night vision devices have strong light protection. However, significant changes in environmental brightness can greatly affect observation. (2) Infrared thermal imaging night vision devices are not affected by light. They can clearly observe target objects whether it is day or night, or during rain, snow, or fog. For this reason, top-tier automotive night vision systems, such as those used by Mercedes-Benz and BMW, employ infrared thermal imagers.
I understand that night vision devices primarily work by amplifying faint ambient light, such as car headlights or moonlight, to create images that appear green or gray, making them suitable for identifying road obstacles in low-light conditions. On the other hand, thermal imaging relies on detecting the heat emitted by objects to construct an image. It doesn't depend on light sources and can accurately display the location of heat sources in complete darkness, often used in vehicle safety systems to detect pedestrians or animals. From an automotive application perspective, night vision devices are more affordable but can be easily affected by ambient light, while thermal imaging is more sensitive but comes with higher costs and slightly blurrier images. Personally, I believe that for nighttime driving safety, thermal imaging can help avoid sudden risks and is worth the investment. In the future, it may be more commonly integrated into high-end vehicle models.
In actual driving, I've tried night vision systems that rely on sensors to amplify light points, such as headlights, to assist imaging, which is suitable for highways but fails in complete darkness. Thermal imaging, on the other hand, directly captures heat and can display the positions of living creatures in wilderness or forests, making it particularly suitable for rural roads. The difference is quite clear: one uses light and the other uses heat technology. I think in terms of safety, thermal imaging is more reliable for reducing accidents, but it's more expensive, while night vision is more commonly used in ordinary cars. Nowadays, some new cars combine both to enhance nighttime visibility. If I were to choose an accessory, I would lean towards thermal imaging because of its higher practicality, especially in foggy conditions where it can provide earlier warnings.
