A new video from the European Space Agency (ESA) provides step-by-step instructions for how to modify an inexpensive webcam so that it sees infrared light.
The best webcams for this hack are those that have manual focusing rings, an ESA spokesperson says in the video, which is part of the agency's "Teach with space" project. The ring can be removed to give easy access to the camera lens and the infrared filter. Most cameras have infrared filters, which block infrared light so that they capture the clearest images. To make a webcam see infrared light instead of just light on the visible spectrum, you'll need to remove that filter.
Step one, then, is to remove the manual focusing ring on the outside of your camera''s lens. Once that is done, you'll see a piece of glass with a red-green tint, according to the ESA spokesperson. That's the filter you'll need to remove.