Textbook in PDF format This brief overviews the application and significance of high-speed photography in experimental fluid mechanics, specifically focusing on the detailed observation and analysis of bubble dynamics, drop dynamics, and wake dynamics. It explores the development and various application scenarios of high-speed imaging technology, using it to investigate microscopic phenomena within these areas. The book covers key topics such as bubble collapse and deformation, particle acceleration mechanisms, and cavitating flow patterns in bubble dynamics; droplet impact, coalescence, and fragmentation in drop dynamics; and the wake phenomena of bluff bodies during translation, rotation, and interactions with flat surfaces in wake dynamics. Through experimental observations and mechanism research, the book provides insights into the underlying processes and behaviors in fluid systems, making it a valuable resource for researchers and students in fluid mechanics and energy related fields