In most secondary physics textbooks, waves are first introduced with examples of mechanical waves
because they can be illustrated by drawings and photographs. However, these illustrations are static
and cannot reflect the dynamic nature of waves. Although many mechanical waves (e.g. water waves and
vibrating strings) can be easily shown using school apparatus, their motions are too rapid to
observe clearly. Computer simulation is a solution but is not ‘real’. This article describes how a
consumer-type high-speed digital camera can be used visually slowing the motion of some wave
experiments. Several techniques to further improve the visibility of the video content are also
described.