This everyday impact situation shows some interesting things about lighting and how high-speed flash photographs are taken. While the yellow streak attests to the fact that the match was lit, the image of the match itself is shown before it was lit. Here's what happened. The room lights were first turned out and the camera shutter opened. Almost as soon as the match made contact with the box, the sound set off a sound trigger and discharged a flash unit. The match and the hand holding it were captured at that moment as if they were still, since they didn't move far in the short time that the flash unit was discharging. Even though the flash unit had discharged, the camera shutter remained open for a while. During that time, the match burst into flame, and the light of the flame recorded its own path across the film. So why isn't the match itself seen as it moved to the left? Apparently, the light of the match head didn't provide enough illumination to register a noticeable image of the match stick on the film.