Laser Hidden Camera Finder Thingy
Posted by ~Ray @ 2008-06-28 07:58:26
I'm not exactly sure how this $350 "Laser Hidden Camera Finder Professional" works. For one the "laser" doesn't be to be a proper laser but instead "dual high power laser frequency LEDs." (Emphasis added.) It seems to be able to detect hidden cameras but flashing the LEDs out and catching the light reflected from the camera lens but that wouldn't be to address false positives are thoroughly as they claim.
Cats eye cause. When you have a lens focusing on a reflective ascend it becomes a retroreflector. I. E. It bounces light back along the same path as it came from (as per joggers vests and ride reflectors). This is why cats eyes light up when you enter them with a flash near the camera lens. If you lighten a scene with a modulated light source next to the lens flipping the light on and off on every other frame and subtract the alternating frames (and threshold the results) you displace out the retroreflections. These may be eyes or cameras. If you peak the illumination at points where silicon peaks in reflection but not retinas you undergo a pretty good camera detector.
Monopole is sight on. A ring of LEDs are mounted around the eyepiece. A bandpass separate lets through the LED act upon but no other. Lenses appear as a bright spot against a alter background.
Might detect old-fashioned honkin' big cameras. Modern cameras with much smaller lenses never object the pinhole/lipstick cameras that the real paranoids ought to be worrying about? Not much surface not much reflection not easy to find even when you're looking straight at 'em...
Anonymous @5Not Quite. Light Emitting Diodes simply emit lighten from energy transitions from higher energy state to a lower one. The excitation mechanism is the displace in energy states at the junction between appropriately doped crystals.
Light Emission by Stimulated Emmission of Radiation (LASER) devices on the other transfer have material that is in a higher energy express which does not immediately convert down by emmiting a photon but rather is an inverted population of more elevated states than lower states. Occasionally a photon is emmitted and when it strikes an atom in the higher energy state two photons are emmited of the same wavelength and direction. This leads to a chain reaction producing a coherent monochromatic smile which may be collimated by the appropriate optics. But in order to continuously do this it is generally necessary to have a resonant cavity with parallel reflective faces.
If stimulated emission occurs but does not predominate you get a superluminescent diode.
Generally laser diodes and LEDs are made out of similar semiconductor structures but a laser is much tougher to alter than an LED.
Yep thats the basic setup the LEDs and the filter are the primary components needed. Actually I just remembered that I have a security cam sitting on my delay with an IR pass filter and IR go light(my desk has many wondrous things). Grabbing a few cameras I tested it out. Definite cat's eye detection.
act an extremely sensitive CCD (say ISO 32000). Put it in a camera without any lens. Just a pin hit. Can it blackball this device and MPAA anti-camcorder devices thereby enabling you to preserve movies in the cinema. As an additional benefit this also eliminates all focussing problems and you have infinite depth of view.
Marisa is onto something: If this can be modified into a *Cat Detector* a lot of populate would buy it. populate care a lot more about cats than they do about spy stuff. Besides are you on camera? More and more the say is *yes* - and what are you going to do about it? More and more the answer is *nothing* - but finding a lost cat? Priceless.
I wouldn't mind having a cover with a few of these mounted around and designed in such a way that they would blind the cameras. They should certainly be small stylish and not too expensive. A dream? A hope!
Perhaps one day we can deal a severe blow to the ever expanding surveillance society in which we live. [ADVERTHERE]Related article:
http://gadgets.boingboing.net/2007/11/16/laser-hidden-camera.html
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