We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
Simple Electronic Devices for
High-Speed Photography and Cinematography
Bv P. FAYOLLE and P. NASLIN
Described are a basic electronic flash and delay circuit and its applications to shadow and reflected-light photography, Kerr-cell shutters and ultrahigh-speed cinematography in conjunction with the Cranz optical setup.
E
ILECTRICAL METHODS of high-speed photography and cinematography are by no means new. More than 70 years ago Mach and Cranz used the electrical spark to photograph bullets and shock waves with exposure times of the order of 1 /isec and thus founded experimental ballistics. In 1903, at the Marey Institute, Paris, Lucien Bull analyzed the flight of insects at rates of several thousand frames/sec. His rotatingdrum camera triggered a spark-gap via a rotating switch and an induction coil. He thus established a long-unbroken record in high-speed cinematography at a time when normal-rate motion pictures were hardly born. He later achieved rates of many thousand frames/ sec, using a relaxation high-voltage discharge circuit and a rotating-mirror camera. No notable progress was made
Presented on October 8, 1952, at the Society's Convention at Washington, D. C., by P. Naslin, who read the paper, and P. Fayolle, Laboratoire Central de 1'Armement, Place St. Thomas d'Aquin, Paris, France.
(This paper was received first Dec. 23, 1952, and in revised form on Mar. 19, 1953.)
until 1929, when the Cranz-Schardin multiple-discharge circuits and optical setup made it possible to obtain a few dozen high-definition pictures at rates up to several million frames/sec.
The achievements of these and other pioneers in the field are perhaps more remarkable than anything achieved since, because they had accurately to initiate and control high-voltage phenomena by purely electrical means, without the help of fast-response and flexible electronic devices.
The French Central Laboratory of Armaments in Paris also took part in the development of the methods of spark photography between World Wars I and II. P. Nicolau and P. Libessart,1-2 both generals today, used them successfully for wind-tunnel work and for the investigation of ballistic phenomena. This work was continued during the German occupation of France by the authors of this paper, under cover of industrial research such as the study of vibrations and failure of mechanical parts.
Since VE Day, we have been faced with the task of providing our research
May 1953 Journal of the SMPTE Vol.
60
603