The study and analysis of fluid dynamics is a difficult task. This webinar presents recent technological advances high-speed video cameras and their applications in experimental fluid mechanics. High-speed imaging is in popular demand for a broad range of experiments in fluids. It allows for a detailed visualization of the event under study by acquiring a series of image frames captured at high temporal and spatial resolution. Following a brief review of the various high-speed camera types, we point out the advantages of the latest technology. The webinar covers high-speed imaging basics, by defining criteria for high-speed imaging experiments in fluids and to give rule of thumbs for a series of cases. It also considers stroboscopic imaging, triggering and illumination, and scaling issues. Then we show examples of how these cameras are leading to new innovations in the study of flows. High speed cameras are vital in measuring the complex behaviour of liquids, gases, and plasmas in motion. The selection of a high-speed imaging system for the application and ultra-high-speed imaging at frame rates exceeding 1 million frames per second is discussed. We briefly discuss the digital high speed imaging of cavitation bubbles and bubbles from a vertical nozzle and breakthroughs in fluid dynamics when it comes to medical research.