OK, try the following: Take your digital camera or webcam, and put it in preview mode. Whilst watching the screen, point a remote control at the lens and press a button on it. Why does it light up so bright? Why will a digital camera pick up this in a way our eyes can see it when our eyes can't see it normally? You think that's good... you know those big security cameras with infra-red tracking for nightvision... look at one of them through it!!! It's like a floodlight! Explanation?