how do thermal cameras even work
In: Technology
On the level of the device, a thermal camera is just a camera, like any other, just optimised for a wider range infrared light rather than primarily visible. But the basic principle is the same, you have a sensor that detects light and makes an image. Many regular camera sensors actually need infrared filters to block out infrared loght, that’s how similar they are.
Now, why that makes it a “thermal” camera. EVERYTHING made of atoms emits light. We don’t normally notice that because the frequency of that light (or more specifically, the range of frequencies, not just one) is related to its temperature, hence “thermal radiation”, which for our everyday temperatures is some shade of infrared. But that’s also why really hot things visibly glow.
And importantly, that relationship between temperature and frequencies of light is really well established, to the point where we can just plainly tell the temperature of something by the thermal radiation it emits.
Note, this is in contrast to non-thermal radiation, light emitted by some other mechanism, for example an LED, coloured fireworks or fluorescent paint. So you can confuse a thermal camera by pointing it at a bunch of LEDS.
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