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Comment by hyperstar | Hacker News Reader

What are the best ways of doing this without a smartphone?

The free option: use your smartphone's flashlight and try to spot unnaturally bright / colored reflection.

If you want to spend some money and don't mind carrying an extra device: probably any of the "hidden camera detectors" on the market will be at least somewhat useful. K18, CC308+, etc.

We're trying with our work to get better or at least equivalent results without having to use external devices.

Put a very bright light source next to the spot you don't want to be caught in a camera. The viewer would only see a ball of light.

I don't think this works, mainly because an extremely bright external source of 850 nm light looks incredibly suspicious through the sensor (as we expect the ToF sensor to be the only light source). We could add that check in explicitly.

I think the bright light is intended as a countermeasure to the hidden camera, not as a countermeasure to finding the hidden camera.

Basically, to keep position X unobservable through the hidden camera, ensure that there is an overwhelming source of photons between position X and the hidden camera.

Since we don't know where the hidden camera is, the best we cam do is to assume that the immediate vicinity of the bright light will accomplish this.

Oh, I must have misunderstand, since the root comment was talking about detection methods. But yes, jamming is a good option, and there have been papers to make areas "unrecordable". I don't have my citation manager on hand now, but I think it was an early ACM Sensys / Mobisys research work.

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