Practical Issues

Of course nowadays all respectable experiments must employ a laser; you can hardly walk down the street without one.Sir Brian Flowers, in Proc. 11th Intl. Congr. on High-Speed PhotographyLight sources have improved tremendously since Hooke’s first candle-illuminated schlieren system. Combustion lamps eventually gave way to electric sparks, arcs, and filaments, which were then supplemented by coherent and solid-state devices. There is now an expansive literature on the topic that needs no thorough review here. Instead some key references are cited, followed by a brief treatment of the important lamp types for schlieren and shadowgraphy.