I’ve teamed up with Benji Canning-Pereira to create a method of evading digital cameras. Digital sensors like cameras are tuned to see about the same frequency range as human eyes. There is, however, a small band of light that is invisible to the human eye that digital cameras are very sensitive to. It is called Near Infrared and it picks up where our red range drops off. It isn’t full Infrared, but the last remnants of color before the scale slips into the radiance of heat.
NearIR is typically used with security cameras so they can see in the dark. Often, you will see an array of IR LEDs around a security camera’s lens. But since you (with your human eyes) can’t see the light emitted, they appear to be off. Some IR emitters produce a small amount of visible red light at the light source but you really have to look for it to notice it. A simple way to find out if there is a night-vision capable camera near you is to look through your cell phone camera.
The picture on the left was taken outside of my apartment. If you look above the white brick in the center of the picture, you can see a little purple ring of lights. These IR lights surrounding the lens produce a shadowless night-vision image for the security camera. This was taken with my iPhone4 which has an IR filter in it. As you can see, even with a filter, the light is still detectable.
Since we know that the cameras are sensitive to this type of IR, we can use IR to evade this camera. By producing more light than the camera emits, we can blow out the image with an IR hotspot. It would be awkward and obvious to walk around pointing an array of IR lights at cameras. Not only would you have to manage the equipment, but you would also have to be very aware of where the cameras were, thus drawing more attention to yourself. To avoid this we must create a discrete system that can fit into our natural environment and still accomplish the task of hiding in plain site.
Benji and I have created a prototype of a necklace that accomplishes this. Within the necklace are embedded a series of low voltage IR emitters which are laid out in such a way that IR light is abundant at any viewing angle of the face. The necklace is also very low profile so it doesn’t draw any extra attention for the wearer. The necklace is powered by a single AA battery which is discreetly embedded in the ribbon of the necklace. While this is a very low emission of IR light, the concept is clear and with the addition of higher powered lights, one could easily “erase” their face and exposed skin using this method.
You can see that up close the IR emitters appear blazing hot and flare the lens a bit causing distortion over the face of the wearer. The emitters used in the prototype are very small with a narrow angle of view. If the jewelry had more powerful emitters (say 300W), the wearer’s image could be completely obscured, giving them a low profile way of remaining anonymous to cameras without drawing attention to themselves publicly.
In constructing the necklace, we wanted to make sure that the array of almost 20 LEDs was undetectable and reliable, electronically. The circuit is a simple parallel setup and runs off of a single AA battery. This keeps it efficient, light weight and small. The circuit could be applied to any kind of jewelry to extend the effect. Earrings would distort side views of the face, while necklaces, glasses and facial piercings obscure frontal views of the face. Rings, bracelets and cufflinks could be used to obscure skin color by distorting the image of the wearer’s hands.
This method is simple, cheap and reliable. It can be recreated with very little expertise, making it accessible to all who want to augment their jewelry to push back a little against the millions of cameras observing them.