Electronic flash (strobe), does indeed give out a lot of infra-red radiation. Sunpak used to do a version of their 5000 hammerhead gun with an infra-red filter permanently over the tube, I think it was designed for surveillance use. If a visible flash is no problem, a filter over the camera lens should have the same effect.(posted 8877 days ago)I've just checked, and Sunpak still list an infra-red head for their 622 professional gun.