On my website are some instructions for converting a web cam to for cheap, easy infrared photography. Basically, all digital cameras are capable of detecting infrared radiation just outside of the visible spectrum. That is to say light with a longer wavelength than the red end of the spectrum. With some slight modification we can filter out the visible light and let through the infrared light. This will not allow you to do thermal imaging, which is done in the far infra red.The web cam I used was designed for use in low light. It includes six IR LEDs. More importantly, since it was designed to work with IR LEDs it lacks the IR filter that most digital cameras include. The IR filter found in digital cameras helps keep colors more consistent at all light levels. Consequently it blocks most of the light we're interested in for this project. A quick Google Search will reveal several places that sell the exact same camera I used (some for under $10).
