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Hidden Camera in Lights (ON)

Inside a light bulb that's on
  [vote for,

OK. Hidden camera, big deal right?

But, there's many ways to spot a hidden camera, as they all need line of sight. Those dark glass bulbs are obvious. In a featureless hallway, you can spot hidden cameras easy. And, they all need housing for the parts.

Here's the twist, you can hide the camera inside a light bulb that's ON. In a flashlight, in a ceiling light, etc.

There are at least 2 different ways to do this:

1. Have the picture frame capture rate, to happen at collection intervals that are 180 degrees out of phase with the natural AC peaks of the power source for the light filament. (Current capture rates are certainly within 60 Hz for AC = 0.016 seconds exposure)


2. Have the camera filter out the light frequency signature of the bulb itself (to subtract the noise of reflected light within the bulb). This would allow for longer exposures.

In either case, the bulb can already be designed to take the nearly point-source of the filament and spread it to the space, so that same illuminated space would then re-focus the returned light (to capture as an image) near the same spot where the filament is. So, a minor off-center of the filament, with a small camera (mini CCD) just oppositely off-center should get a pretty good image quality.

sophocles, Feb 08 2007


       [Ian] - it is, in the sense of light interference, which is just addition of the waveforms. You don't notice any systematic interference pattern as in school "two slit" experiments because the light source is large, not coherent, and not single-frequency (you're not large and incoherent, Ian, just the light reflected off you).

Method 1 above wouldn't work, because the bulb filament continues glowing throughout the AC cycle, because it's hot.
hippo, Feb 08 2007

       Firstly, lights don't ficker on and off in an ac current, they just get hot and glow. I think it should be possible to shade the camera from the light in some way though.   

       It's handy that you have a ready power source, I believe you can also use power cables to transmit data by varying the amount of energy consumed and monitoring it elsewhere. I think LG do it with washing machines.
marklar, Feb 08 2007

       OK/right about that filament being hot. Scratch #1 method then unless there are lights that really flicker... (Do fluorescents really flicker on/off at a constant rate?)
sophocles, Feb 08 2007

       I'm not sure that any sort of frequency filter would work either. Since any colors you (or the camera) see are reflected light coming from the bulb (assuming a single light source) any attempt to filter out the light frequencies would also filter out the returning light from the object being observed. This could be solved by using either multiple light sources (track lighting or such) with differing frequencies, or a camera that picks up an IR frequency that is not generated by the bulb, but is generated by the object being observed (body heat). But neither of these would produce clear normal color images.
MechE, Feb 09 2007

       Frequency shouldn't be too hard to filter on. After all, you know the signature of frequencies from the bulb, and can subtract those out.   

       What you're shining the light on may not be dark already, so the reflected light would be enough from other sources to pickup on.
sophocles, Feb 14 2007


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