How to make a webcam work in infra red

The camera

The camera used for this experiment was a Sweex USB Webcam this camera was chosen for it's price and availability. IE I didn't mind too much if I killed it and it was sat on the desk at the time.
The adverts at the top should show some providers of cheap webcams, and buying from these people will help to pay my hosting costs.

As an added bonus, but nothing to do with this project, this camera works fine under Linux with a 2.6 Kernel (I'm using 2.6.8) using the sonixcam driver from here.

Conversion

Step 1 (Sweex specific)

Remove the crappy plastic stand. - try not to lose the little rubber bits from the holes in the camera sides. I think they are supposed to stop it from tilting upwards under the weight of the wire. Shame they don't work really.

Step 2 (possibly also Sweex specific)

Remove the screws. If your chosen victim webcam is held together in some other way you'll have to figure it out yourself.

Step 3 (Probably not Sweex specific)

Prize the casing apart.

Step 4 (Kind of Sweex Specific)

If the Lens will not unscrew without removing the PCB (Like on the Sweex) then remove the PCB. It probably only slides in anyway.

Step 5 (Almost certainly not Sweex specific)

Unscrew the lens assembly from it's holder. The focus on most webcams is achieved using the screw thread that is also used to hold the lens in. Turning it enough times will unscrew it completely. All camera's I've ever met won't let you do this without opening the case. The bit that comes out of the sweex looks like this.

Step 6 (Doesn't appear to be Sweex specific)

Looking at the lens assembly in the picture you can see a small square of glass stuck in the back. Though it appears clear in the picture above, it has a red tint to the eye as shown here.
I've looked in a Creative camera and seen the same thing there but theirs is round. This piece of glass is the Infra Red Filter. It stops IR light getting through to the sensor. For our purpose this is bad so remove this piece of glass. Removing a square one like the Sweex is easy but I suspect the creative round one is harder.

Mitch White has this to say on the Alaris weeCam ...the filter is actually "painted" on one of the lenses. At first I thought I wouldn't be able to remove the filter, but I tried scratching at it with my fingernail, and it started to come off! So, after scratching off all the redish stuff, I reassembled the camera and it works perfectly!

Ken R has converted a Creative camera though not the same as mine. Click here for his instructions on adapting the lens assembly.

Newer Sweex models and many others have a lens design with a cross section like this.
Don't you just love MS Paint.
On here, the red is the IR filter, the green bit on here is a small plastic collar that holds things together. It looks at first glace like the same piece of plastic as the main lens holder assembly. This can be removed by levering it out with a sharp knife. This collar can be used to hold the new IR pass filter in place later.

Step 7 (Not at all sweex specific)

Now we need to make a new filter only we want one that blocks visible light and only lets IR through.
Dig out your holiday snaps and look at the negatives. NOTE: they must be colour negatives, black and white ones won't work. Find a bit of absolute black, you can usually find a bit before the real photo's start. Make sure it's really black, a part of a normal photo may not be good enough.
Cut two small bits out similar in size to the IR filter that you just removed.

Step 8 (Also not at all sweex specific)

Fit the two bits of film where the old filter was.

Step 9 (No idea if it's Sweex specific)

Do something to hold the bits of film in place. I used a little bit of wire as shown rather blurredly here. If you use superglue for this be careful not to get any on the actual lens or the part of the negatives that the IR light will pass through.

Step 10 (I'm getting fed up of saying whether it's Sweex specific or not.)

Screw the lens back into the camera PCB.

Step 10

Re-assemble the rest of the camera.

Step 11

Make sure you're using real sunlight or tungsten lighting. Those new fangled high efficency bulbs give out very little IR light.

Step 12

Start up the webcam.

Step 13

Take some pictures.

Here's a few I prepared earlier


My Keyboard lit only by a TV remote control.


My mobile phone using an unmodified webcam.


The same phone in IR.


A polo shirt with a normal webcam.


The same polo shirt with the IR webcam.


An english five pound note in IR. For any non-uk people, the queen's face is not cut in half to the naked eye.
Mariusm has hacked a Logitech QuickCam Pro 4000 and posted a picture of some american money. Click here to see it.


Moses Holmström sent me this picture of a 5 euro note


In Colombia they take it to the extreme.


I tried to get these two shots from exactly the same place.
The rainbow is barely visible to the normal camera, on the IR one it's big, bright and just outside the line of the visible one.
A second rainbow on the IR shot is also clearly visible.


A bottle of Coke in Infra Red is pretty much transparent.


This monitor was on when I took this (running the webcam software on it)


Veins show up well in IR.

A normal picture of the lake at Tollerton Hall.

One day later and in IR.


Spectral Response

The top of this image shows the spectral response of an unmodified digital camera, below is the response of the IR modified camera. This image was taken using a CD as a diffraction grating and a tungsten bulb as the light source. Thought the method was not very scientific and the accuracy may be suspect, it gives some indication of the efficency of film as an IR filter.


Other People's Pages.

Yigit Guler has made a very detailed page about hacking some Sony camera phones.

Robert Gordon has taken the whole thing mobile.

Bad Ace Tech Show have some video (near the bottom of the page)

Bill Koch has some good comparison shots here.

Peter has an IR camera spying on his cat's hideaway.

Further Reading.

Doing this to a standalone Digital Camera.

For a detailed description of how CMOS image sensors work take a look at this CMOS sensor Primer

This is a typical Image sensor Datasheet. Very technical but it does have a nice graph of the spectral response of the sensor up to 700nm. Hynix Semiconductor CMOS Image Sensor HV7131E1 Datasheet (PDF)

The bottom graph on this page shows the absorbtion spectra of a colour negative.



Known good and bad webcams

Known good Cameras
CameraHackerNotes
Alaris weeCamMitch WhiteSee above RE:filter
Creative NX ProMoses Holmström
Dexxa WebcamJames S A Glover
IBM PC WebcamJorge DominguezThe filter is hard to find
IBM PC WebcamSaint Aardvark the Carpeted Excellent name - more info here
ICatch (VI)Smidge204A press fit plastic ring holds the filter
Old Logitechschmu
Logitech Quickcam ZoomEric Andersen
Sony EyetoyReggie Sanderson
Quickcam ExpressJeromeAnother Logitech success?
Older Philips USB model (not the sound one)Lawrence McG
Old Creative WebcamKen RaltoSee sub page about the filter
Vgear2 MinicamMick
Nexxtech mini digital cameraJames JacksonMini standalone digital camera
Oregon Scientific FlashcamMeStandalone camera. Had to scrape lens
Logitech Quickcam ChatLee vonKrausInstructions here.
Trust Spyc@m 100Jorrit Kronjee
Ge MiniCam Pro.Mack Higgins
Swex New DesignJohnnyAs mentioned earlier.
DSE (Dick Smith Electronics) webcamPaul B
Cool-i-cam (blue micro edition)Jared Belkus
Logitech QuickCam MessengerDaniel Nickels
GE HO98064Richard Lee
Genius VideoCam LookJJ
Philips ToUcam IIArtturi Vuorinen a.k.a. Saipher a.k.a. Cypher
Micro Innovations Micro Webcam MobileBrian Shacklett
PC Line PC Cam 300aKristiaan Davies
Trust spacecam 120Andreas Gustavsson
Kodak DVC 323James TsengI believe this is a standalone digicam.
Logitech quickcam messengerPix
Argos WebCam with MicrophoneMark Everingham
Q-TEC 100 USBPeter
Orite MC310Onur AkgunScrape the filter off.
GSm@rt A30 CameraJeremy Shepard"Was a total pain in the ass."
ICatch (VI)Smidge204
Fuji Finepix 1300mark hoekstraFull story here.
Quickcam Pro 4000Jim MunroRemove the adjustment lens and push the filter out
Logitech Quickcam Sphere
Called Quickcam Orbit in the US
RamonVery expensive to do this with
Need to cut the filter out
Philips PCVC740K ToUcam ProPeter Barr
Cameras where only some work
CameraNotes
Logitech QuickCam ExpressWorked for Brandon H
Cameras known not to work
CameraHackerNotes
LabTec "Webcam USB PC Camera"Bjoern WielandFilter is a coating on the sensor package
Creative PC-CAM 600Ben Bake
Logitech Quickcam Pro 4000Brian Hansen
Old IBM PC Camera (older than five years)Ross Moffett
Veo StingrayRoss Moffett


Other Projects

I've also played with timelapse filming using a webcam though not an infra red one.
This was filmed at one frame per second (that's as low as the software will go) then fed through the excellent VirtualDub to speed it up 100 times and decimate it to 25 frames per second.

(YouTube Link - opens in new window.)




REALLY simple web server for windows.

The temperature in Nottingham

My Chess Race animation on YouTube (Opens in a new window)

Macro (Close Up) Photography with a hacked digital camera

IP Tunneling on windows.

I'll probably regret this but...
Here's my e-mail address for any comments & questions.


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