A chronicle of improvised infrared filters, useful for anyone who wants to experiment with IR without investing in filters. Also useful to test how well your camera can detect IR and for IR transparent props.
Lighting Gel (excellent) Described here. In my expeirments, a stack of two Congo Blue to one Primary Red gels works almost as well as a low end (Neewer) 720nm IR filter. For use in goggles, I found that three Congo Blue to one Primary Red works best. Your eyes may differ.Floppy Disk (sucks) A section cut from a floppy disk will pass IR and visible wavelengths up to orange. The passband is heavily attenuated. For non engineers, that mean