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Harold E. Edgerton was born in Fremont, Nebraska. He received the Bachelor of Science degree from the University of Nebraska in 1925. After one year with the General Electric Company, he entered the Massachusetts Institute of Technology and has been there, first as student and then as teacher, ever since. He received the .S. degree in 1927 and the hP octor of Science degree in electrical engineering four years later. At that time he was beginning his life's work, prefecting the stroboscope, which has revolutionized ultra-high-speed motion and still photography. Dr. Edgerton organized and helped in the initial operation and management of Edgerton, Germeshausen, and Grier, Inc. (EG&G). He has pioneered the development of flash photography in the ocean depths. Out of this work has grown the sonic probe of the ocean bottom. He has become widely known as an underwater explorer. Above all, Dr. Edgerton is a master teacher who understands well the meaning of relevance and the sources of motivation in education. He is a prolific contributor to scientific journals and the holder of over forty patents. He has received honorary degrees of Doctor of Engineering from the University of Nebraska, and Doctor of Laws from the University of South Carolina. A recipient of numerous awards from the foremost engineering and photographic societies of the world, he is a member of the National Academy of Sciences and the National Academy of Engineering.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Discharge lamps filled with xenon gas through which electrical capacitors are discharged have found many applications for producing pulsed energy in photography and energy discharges. The object of this paper is to review sane of the more important characteristics of flash lamps. The flash duration of specific flash lamps when operated from a given capacitor charged to same known voltage is dis-cussed below. The dimensions of the lamp are one of the most impor-tant factors since the response of the lamp to the circuit is greatly influenced. Experimentally measured flash duration as a function of capacitance and voltage is given in graphical form for one type of flash lamp. Rules (approximate) are given for converting the data into data for other flash lamps and circuits. Efficiency of a xenon lamp can be as high as 5 candela/watt for a lamp that is loaded so that the arc fills the inner diameter of the constraining tube. The life of the xenon lamp can be many, many flashes. In fact, this is one of the lamp's strong points. The spectral distribution of the light from a xenon lamp closely approximates daylight with a small shift to the blue if the applied voltage is high. Details of a specific flash lamp showing the nature of the spectral output is given. A list of some of the oractical uses of electronic flash lamps is given and discussed.

The national delegates to the 12th International Congress on High-Speed Photography, held in Toronto, Canada in 1976, were delighted to receive an invitation from the Japanese delegates to convene in Tokyo during the week of August 20, 1978. Soon, many people were making plans for their attendance and participation. Technical papers have to be written and equipment displays have to be planned. One of the real uses of an International Congress is to force the issue of a preliminary description of one's work. There is nothing like a time deadline to finish a proposed paper! It would be a very good idea to have the complete paper in hand before the summary is written, but who does it that way?

All electronic flash sources have "fast," that is, "short" exposure times compared to conventional shutters. There are many users who do not realize that the effective exposure time is not the same for all flash equipments. This paper discusses the exposure time and how it is influenced by the electrical characteristics of the flash lamp, and the electrical discharge circuit. It is pointed out that the "exposure time" of many electronic flash lamps is entirely too long for some applications. The "blur" experienced in a photograph of each subject is directly due to the exposure time, and the velocity of the subject. It is obvious that photographs of people do not require as short an exposure as does the photography of a fast moving bullet. Most of the imporant factors influencing the flash-duration of electronic flash lamps will be discussed in detail. Specialized equipment for bullet and bird photography, where extra short exposure times are important, will also be described.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.