Night vision cameras often use infrared, because low light imaging used by night vision cameras is not clear enough and cannot provide long-distance detecting in total darkness at night, but infrared cameras can. The biggest advantage of infrared cameras is that it is much better at spotting and tracing objects. Visible light devices and night vision cameras with low light imaging cannot see the target hidden in the grass or forest. However, with infrared cameras, the infrared radiation of the targets which stands for heat would go through the covering material and can be clearly seen.
Thermal imagers can detect everything has infrared radiation which is over -273.15℃. Thus, you can see the targets in total darkness without any visible light during both day and night. What's more, thermal imager can highlight and tracing the targets quickly. And thermal imagers can see through smoke, fog, dust, so targets are nowhere to hide. Traditional night vision relies on the visible light reflected by the environment at night. So darkness will limit the detecting distance and clarity of night vision. At night or in dark environments, traditional night vision cannot see as far as thermal thermal images. Overall, thermal imagers have better performance than night vision devices for hunting and observing at night.