People normally do this by scanning a 10mW 832nm laser with a mirror, according to Dan Gelbart in https://www.youtube.com/watch?v=0MtRxX0crjU. The lecture is 77 minutes, covering nonlinear junction detectors, digital calipers, the US-embassy bug in Russia, laser microphones bounced off windows, and geometric errors from material relaxation. The bit about camera detectors is close to the end. Works for eyeballs too.
Lensless sensors (for example, using compressed sensing, or Hadamard shadow masks) can presumably defeat this, but also, watching from far enough away should defeat it. Hard to do that inside a pervert's AirBNB, though.
kragen
Until someone develops hidden cameras with AI that will be auto turned on couple of hours later after detecting presence at that time a scan was already performed and nothing was found.....
carlostkd
Using the phone's existing LED for this is clever. Wonder if the 'AI' is genuinely learning or just a sophisticated reflection analysis.
Wendell58
Wonder if it handles the really tiny pinholes effectively. For now, a thermal camera feels more robust for peace of mind.
thimble_io
If this worked with IR, and so non visible, it might be even more useful.
Great idea though.
fidotron
Another strategy that's often used is to cause motion then detect the resulting transmission spike. That's also defeatable of course (cache+burst, CBR, etc).
The ideal detector should incorporate multiple methods. Someone should make a site that rates these for each detection method then adds them into an overall score.
gruntled-worker
I wonder if it works with smart glasses.
brunoborges
Can't a thermal camera can do this? It should be able to detect any difference in ambient temp, even a few degrees, and a CMOS sensor gets warm, not to mention any wireless transmitters, power sources, and ICs. Turn off everything in the room and walk around with a ~$100 ali express handheld thermal camera.
comments (9)
Lensless sensors (for example, using compressed sensing, or Hadamard shadow masks) can presumably defeat this, but also, watching from far enough away should defeat it. Hard to do that inside a pervert's AirBNB, though.
kragen
carlostkd
Wendell58
thimble_io
Great idea though.
fidotron
The ideal detector should incorporate multiple methods. Someone should make a site that rates these for each detection method then adds them into an overall score.
gruntled-worker
brunoborges
Eisenstein
throwaway81523