A couple of weekends ago I felt like hacking some hardware. I had seen a series of tutorials online about converting a regular web cam to work with the Infra-Red spectrum and thought I'd give it ago. If you haven't seen the guides they can easily be found through your favourite search engine.
The nature of the hack is quite simple. The CMOS (image sensor) within the web cam is sensitive to a wide frequency of colours and the manufactures of web cams use a simple filter to block infra-red light and allow through the visible (coloured) spectrum of light. By replacing the filter with one that blocks visible light and lets through Infra-Red we have converted the Web-Cam to one that captures Infra-Red. It appears that most web-cams lent themselves to this trick - so just grab one at random and give it a go.
I managed to find a web-cam by making a trip to my local second-hand/games exchange shop. On sale was a second-hand Eye-Toy for £9. I knew how to set up the Eye-Toy on the PC, but if you don't you can read these instructions. These web-cams are of a surprisingly high quality, and I'd recommend them as for a second hand camera, you won't find a cheaper on to play with.
Apart from a web cam, you will need a black part of a negative, some Super-glue and some simple tools.
We will use the black part of a negative to act as a visible light filter. I didn't have any negatives to hand so I went to my local Snapy-Snaps and just asked for a part from the start of the film.
Converting the camera
Step 1 - Take off all the casing.
Just use a small Philips screwdriver to get the bottom half of the case off.
Step 2 - Pull off the focus adjusting wheel
To do this just push in one of the clips that hold it in place. The ring should just snap out.
Step 3 - Take off the Lens assembly
Just unscrew the unit, as if adjusting the focus of the camera. Gradually it will move away from the circuit board and come loose.
Step 4 - Take off the filter cap
If you angle the lens assembly whilst looking at the rear of the unit you should see the Infra-Red filter glint red. We need to replace this. Just after the last of the thread, you should see a small split line, carefully put a scalpel in this line and pop-off the thin cap that holds the lens in place.
Step 5 - Replace the filter
Take out the small square of glass that is in the lens assembly and cut out some negative the same size. Put this negative back where the filter was, and glue down the filter cap. Super glue will end up covering the lens if your not careful and destroy the whole camera. The best advice is to apply the glue with a match to bottom of each of the lugs found on the filter cap.
Step 6 - Put the whole thing back together
Hopefully you've not lost any screws!
Testing the Camera
The camera is now set up for Infra Red, it will appear in black and white through your computer. A quick test is to use any remote control to view the LED show up.