Sunglasses that Hide your Face from Cameras

Clever. Article and video:

They work by mounting two small infrared lights on the front. The wearer is completely inconspicuous to the human eye, but cameras only see a big white blur where your face should be.

Building them is a snap: just take a pair of sunglasses, attach two small but powerful IR LEDS to two pairs of wires, one wire per LED. Then attach the LEDs to the glasses; the video suggests making a hole in the rim of the glasses to embed the LEDs. Glue or otherwise affix the wires to the temples of the glasses. At the end of the temples, attach lithium batteries. They should make contact with the black wire, but the red wires should be left suspended near the batteries without making contact. When you put them on the red wire makes contact, turning the lights on. It's functional, but we're thinking that installing an on/off switch would be more elegant and it would allow you to wear them without depleting the batteries.

EDITED TO ADD (7/8): Doubts have been raised about whether this works as advertised against paparazzi cameras. I can't tell for sure one way or the other.

Posted on July 7, 2008 at 1:54 PM • 44 Comments

Comments

Kevin D. S.July 7, 2008 2:25 PM

Hmm - I wonder if one or two LEDs placed at the collar would be enough to do the trick? A crafty individual could make a small apparatus to clip beneath the collar of a dress shirt... so you don't look like a tool walking around with sunglasses all day. (The bluetooth earpiece already fills that role!)

Paolo GastiJuly 7, 2008 2:42 PM

Wonder if the same trick can be used to fool speed cameras if you put enough LEDs around your number plate...

Alice Bevan–McGregorJuly 7, 2008 4:45 PM

Most, if not all cameras, with the exception of specific "night vision" cameras which utilize IR reflection to capture an image in the dark, have filters placed on the sensor itself to filter out infra-red light. My D200 is particularly insensitive to IR.

I've long thought about the design of an IR-grenade; a ball covered in IR LEDs with a core battery, which you can turn on and throw into a room to blind cameras. Alternatives like IR pen lasers directed at the camera lens seem a little more practical to me.

Greg RJuly 7, 2008 4:49 PM

A (vaguely) related trick that I've heard of is to use optical slave flashes and place them near things you don't want photographed. When a photographer tries to take a picture with a flash, the slave detects it and flashes back, over exposing the image.

Like most counter-measures, it can be foiled by a skilled adversary (simply by not using the flash). But that is beyond the abilities of almost all amateur photographers (and some professionals).

zarixJuly 7, 2008 4:50 PM

@Paolo Gasti

That would get you into trouble in the UK.

Obscuring plates is illegal here, and you would be spotted fairly quickly on motorway traffic monitoring cameras.

Police cars are fitted with video cameras that can see in IR as well, so you would probably be spotted by the first car you passed. On the plus side you hardly ever see them these days...


PidgeJuly 7, 2008 4:52 PM

Characters in Cory Doctorow's short story 'I, Robot' use this technique to avoid detection by the image recognition algorithms watching the cameras of a future totalitarian state, allowing them to move around "invisibly". - http://craphound.com/overclocked/...

thiefhunterJuly 7, 2008 4:56 PM

If this works, the more it's posted, the more thieves will learn of it. If it doesn't work, HAH! I love the thought of thieves walking into crime scene with their protective sunglasses, thinking they're safe and anonymous.

Clive RobinsonJuly 7, 2008 5:04 PM

To all the neigh sayers sorry but with some cameras it does indead work.

It all boils down to how much money you are prepared to pay for your camera it's lens and any IR filters you might wish to include (and even the most expensive of cameras can be defeated if you know what you are doing).

Cheap BW CCTV's using silicon based sensors are considerably more sensitive to IR than you would think, likewise home video camcorders etc (especialy with low light options where the IR filter is switched out).

The easy way to demonstrate this is to set your camera up in a room and connect it up to your TV then take your TV remote control stand in front of the camera point the remote control at the camera lens and press a button whilst looking at the TV screen you will usually see bright white flashes where the remote control is.

Also those very expensive little CCTV detectors use a high power pulsed IR source (occasionaly laser diode) that uses the internal reflection principle (red eye / rodent eyes in head lights) to detect a focused lens and sensor of a CCTV camera and they are very effective. If you realy do have a lot of money you can get one which has an integral high sensitivity heat sensor that also will pick up the heat being disipated by the electronics of a concealed camera/transmitter.

And for those further doubters why do you think you can buy CCTV cameras with integral rings of IR LEDs to use in the dark to distances of upto 30 meters from your local hardware store.

Which gives me a thought, you can get some very small BW cameras. Small enough to be mounted behind the bridge of your sun glasses and as it's lens is behind the out facing LEDs it will not be directly effected by them, but if you are having a clandestine chat down the proverbial dark alley then it will be more than sufficient to illuminate your opposit numbers face.

Oh and in the case of some sunglasses their lenses are transparent to IR...

Have fun and if you realy do want to stop a CCTV dead in it's tracks, get hold of one of the older green laser pointers and take the wavelength converter crystal out of it which leaves you with a laser diode with 50mW or more output, focus this through a cheap "telescope" (golf range finder) and point it directly at the CCTV camera lens. The result if close enough is to damage the camera sensor in cheaper CCTVs at other ranges it can effectivly jam it in the same way as having a spotlight pointed in your face.

Even if the camera does have good IR filters as some of rhe more expensive ones do pointing both a green and red laser pointer at the lens is usually enough to stop even the most expensive of CCTV cameras by mucking up the AGC circuit.

clvrmnkyJuly 7, 2008 5:14 PM

@CliveR: I love the term "neigh sayers." I'm picturing rather set-in-their-ways horses refusing to remove their blinders.

John RidleyJuly 7, 2008 6:08 PM

Good idea, it's been done before (saw this online a few months ago) but I'm not sure about the video. I don't think an LED will work on 1.5 volts. Maybe those were 3.6v lithium cells but they didn't look like it.

GeorgiageekJuly 7, 2008 6:30 PM

I have been thinking about doing something similar, but pulse modulating the LED's to both increase peak power and perhaps confusing the sync in the camera or display sweeps. Local "red light" cameras are a big source of revenue for towns with a 2 or 3 second yellow light and then a ticket in the mail.

epp_bJuly 7, 2008 7:08 PM

Am I such a dork that I'm more impressed at how he uses the body as a natural conductor to complete the circuit?

Neigh-sayerJuly 7, 2008 7:28 PM

I think it should be IR LEDs in the eyes of a squid-shaped hat. With green and red laser pointers shooting beams from its tentacles ("pew, pew" noises optional). With slave-flash devices mounted on your shoulders. Nope, no one will notice that.

JamesJuly 7, 2008 8:58 PM

As others have mentioned, modern DSLR cameras have an IR filter which filters out IR light from hitting the sensor.

I believe that glass IR filters to place in front of the lens are availible, that can be utilised on cameras that do not have a IR filter in front of the cameras sensor.

This may work for defeating some inexpensive security cameras, but digital SLR cameras (weapon of choice for paparazzi) won't be so easily beat.

I personally like the idea of an optical slave linked to a flash to overexpose the image of someone taking a photo, but as mentioned, this hinges on the photographer using a flash in the first place.

SparkyJuly 8, 2008 2:37 AM

Indeed, this may of may not work, depending on the camera, but are a few flaws in the "it works with a remote control" argument; it only works if you aim it directly at the camera lens. You could use a more wide-angled LED, but that means you won't get the intensity you need to sufficiently over-expose the CCD.

Also, try the remote control trick outside, in bright sunlight. It won't work, because the relative intensity is much lower.

In other words: you'll need a really high-power, wide-angle IR LEDs, which eat batteries for breakfast and get seriously hot.

A red laser diode from a DVD burner (~250mW, which is a lot!) will pretty much destroy any camera you aim it at, because of the lens, which conveniently focuses the laser beam into a tiny spot on the CCD. Anyone using a DSLR will also be permanently blind when you use this, and because of the reflection of the lens, the person aiming the laser is at serious risk of permanent eye damage, too.

AltaronJuly 8, 2008 4:23 AM

Just try and point a IR device at your standard webcam. Mac users can try opening PhotoBooth and pressing some buttons on their IR-remote that iMacs an MacBook Pros come with. Makes a nice flash on the video...

So it definitely works with some cams!

laser dudeJuly 8, 2008 4:26 AM

@Sparky

The DVD claims only work if you get yourself a good lens system that is well matched for the laser. There beams are too divergent over meters to be really bad, because you see in red you tend to blink and turn away....

Of course a camera as the receiver is a different story....

MarkJuly 8, 2008 4:38 AM

@Alice Bevan–McGregor

Most, if not all cameras, with the exception of specific "night vision" cameras which utilize IR reflection to capture an image in the dark, have filters placed on the sensor itself to filter out infra-red light.

Many video cameras are quite sensitive to both UV and IR. Also security cameras tend not to use IR filters.
The obvious drawback here is that this is effectivly "active jamming". Whilst the camera may not be able to see someone's face it's more attention grabbing, to a camera operator, than a regular mask.

SparkyJuly 8, 2008 6:15 AM

@Laser dude: ofcourse, the laser diode has a lens that produces a highly convergent beam (which ofcourse becomes divergent after a few mm), so you do need a lens or set of lenses to produce a parallel or very slightly convergent beam.

Luckily, this is what most people who don't know what they are doing screw up, along with proper current control, so the laser pointers they produce aren't very dangerous, and the diodes burn out very quickly.

RTJuly 8, 2008 6:45 AM

Ditto to what Mark says. I work in security sales and the vast majority of CCTV cameras are very sensitive to IR. Quite a few of them have built in IR diodes to illuminate the area they are viewing. Large IR illuminators effective up to 500 or more feet are used to flood areas so cameras can easily see while visible light is turned off to reduce light pollution.

While this jamming method will work fine for passive CCTV, in a place like a casino you would be spotted very quickly.

DavidJuly 8, 2008 8:09 AM

@John Ridley
The voltage that an LED requires depends on the type, with short wavelengths (UV, blue) requiring higher voltages than long wavelengths (red, IR). 1.5 volts is quite sufficient for an IR LED.

JSmithJuly 8, 2008 8:23 AM

I have no idea whether it works, but it creates an obvious opportunity for "the authorities" - get an IR-sensitive camera and watch for any strange blobs where faces ought to be - obvious suspects.

MikeAJuly 8, 2008 10:42 AM

" And for those further doubters why do you think you can buy CCTV cameras with integral rings of IR LEDs to use in the dark to distances of upto 30 meters from your local hardware store."

But my house is at least 100 meters from my local hardware store. Would it still work there? :-)

Greg RJuly 8, 2008 12:27 PM

As far as the comment about hot-filters (what IR-filters are called) in professional DSLRs: There quality varies depending on the camera. The D200 (as I recall) has a very good filter while the S2 has a relatively poor one. (On the up side, this means that I can use it for infrared photography with no modifications.)

For consumer grade cameras the filters, though present, aren't that good. This is a neat idea and would work in the majority of cases for obscuring your face but (as others have noted) would certainly draw attention to you.

JamesJuly 8, 2008 5:12 PM

I wonder if you're better off in general using a bright UV source - even if the CCD doesn't directly register it, you can generate enough radiative noise to effectively render faces indistinguishable. And if the CCD doesn't register the source directly, you can walk around with one without the operators/viewers knowing the source...

Clive RobinsonJuly 9, 2008 9:12 AM

@ James,

"I wonder if you're better off in general using a bright UV source"

Not realy, to block the camera the light source has to get through the optics and then have sufficient energy in the wavelengths the sensor is suseptable in to block it.

Quite a few optics apear to be foggy to UV and others (photography) are deliberatly designed to stop it almost entirely. Also quite importantly a number of fire sensors use UV light to detect petro/alcohol flames so you could set off fire alarms in or around areas which need to rapidly detect hydrocarbon fuel based fires (think petrol stations etc)

Clive RobinsonJuly 9, 2008 9:51 AM

@ aikimark,

"Georgia Tech researchers created an active camera-blinding system"

Having read the page I would say there is absolutly nothing new in their detector design over and above what I described (and is comercialy available already) in my above post of July 7, 2008 5:04 PM.

The only new bit appaears to be the target aquisition and tracking system and white light jamming laser (not good). However as they note it will not work very well (or possibly at all) against "proper SLR" cameras (digital or otherwise). Their stated reason is due to the SLR mirror obscuring the silicon sensor.

Which makes me think that they are using IR spectroscopy to actualy determin if the retroreflective surface is silicon or not (so posibly high sensitivity Galium based sensors won't get picked up ;)

What they do not say is the other reason it will probably not work against high end cameras be it SLR's or Video recorders is that the optics of your camera has to be pointed towards their scanner. So using an appropriate lens with a very narrow field of view from the right angle will probably defeat their system as well.

Also what they do not appear to have considered is how easily their own system will be detected and blocked "Counter Counter Measures (CCM). Detection is fairly easy, either when the detector is scanning or when the blocking laser is used.

When the white light laser fires up it will point back to very very close to their scanning sensor which means they it can easily be seen by a human operator. Further even if the laser does not fire up their detector is active and therefore fairly easily detected.

Counter measures could be as simple as having multiple false targets in view these can be very low tech devices made up as lapel pins (think a clear water LED mounted behind a cheap plastic lens for a home brew one ;)

More high tech would be putting appropriate filters on your camera lense to either stop the detector or even using a high tech specialised filter that stops the narow band component frequencies of the white light laser whilst allowing the broad band frequencies of the film or whatever the target is to pass.

As I said above you can have a lot of fun with these systems without realy trying 8)

SevenProxJuly 11, 2008 3:25 PM

There was talk of using this to blind the cameras of Scientologists wanting to take pictures of Anonymous members at protests.

I think it's crap, though. I'll stick with the traditional mask.

Alexander ElseJuly 16, 2008 4:53 PM

It seems that at least some cameras are not shielded from IR, which of course is invisible to us. You can test this by pointing your television remote control at your cell phone camera. In the case of my Sony-Ericsson w300i the screen appears completely white when the remote is activated. So the IR glasses are at least plausible.

If the camera is shielded against IR then this presumably wouldn't work. I would expect that outdoor cameras are so shielded to avoid being blinded by the sun, but it is quite likely that indoor cameras (of which there are many) omit this in the name of saving money.

Leave a comment

Allowed HTML: <a href="URL"> • <em> <cite> <i> • <strong> <b> • <sub> <sup> • <ul> <ol> <li> • <blockquote> <pre>

Photo of Bruce Schneier by Per Ervland.

Schneier on Security is a personal website. Opinions expressed are not necessarily those of Co3 Systems, Inc..