Just FYI Night Vision versus Thermal Imaging and no they can't see through walls or even clothing, but Thermal Imaging seems to be able to see through smoke and plants?[...]
taking another look at
the exact comparison spot in the video, to me it looks like it does not see through leaves.
the human was just hidden in the shadow and was not visible because of the contrast of the more brightly lit leaves around him, but there were no leaves between the human and the viewer that became transparent in ir.
when the human starts moving it should be especially apparent that ir doesn't see through leaves.
if anything, it rather illustrates that ir cannot even see through leaves, why should we be talking about walls here?
how thin would the wall need to be to feel the heat of the person in the next room on your cheek?
and could you focus the heat so that you could get an image of the person moving?
it is just heat, not x-ray, and to me this discussion starts to sound like 'desperately trying to prove that bricks are soft'.
one of the reasons they use red light for alerts is because low frequency light disperses less in fog than blue light.
ir just disperses even less in fog or smoke than red light.
that probably depends on the size of the smoke particles, or something like that.
even considered that when you walk at night, and someone is, say, round the corner, holding a lit lantern, you can see the light from the lantern on the surroundings even if you do not directly see the person behind the corner.
now, warm objects could act like a light source in ir, like holding a lantern that is only visible in ir.
but i do not seem to notice that effect in the videos, so i am afraid it wouldn't even work that way.