As the tools available to the high speed photographer have become more powerful the underlying technology has increased in complexity and often is beyond the reach of most practitioners in terms of in-the-field troubleshooting or adaptation and this specialization has also driven many systems beyond the reach of high school, community college and undergraduate, non-research funded, universities. In spite of this and with the belief that fundamental techniques, reasoning and approaches have not changed much over the years, several courses in photo-instrumentation at the Imaging and Photographic Technology program at the Rochester Institute of Technology present to a couple dozen undergraduate students a year the principles associated with a various imaging systems and techniques for visualization and data analysis of high speed or "invisible" phenomena.
This paper reviews the objectives and philosophy of these courses in the context of a total imaging technology education. It describes and illustrates current topics included in the program. In brief, calibration and time measurement concepts, instantaneous and repetitive time sampling equipment, various visualization technologies, strip and streak cameras and applications using film and improvised digital recorders, basic velocimetry techniques including sensitometric velocimetry and synchro-ballistic photography plus other related techniques are introduced to undergraduate students.
This paper describes how the operating principles and assemblies associated with high-end imaging devices have been reduced to readily comprehensible concepts as well as affordable, accessible and manipulatable hardware. An inexpensive had-operated scanner was modified to perform imaging applications that are generally associated with high end equipment.
KEYWORDS: Photography, High speed photography, Cameras, Camera shutters, Imaging systems, Control systems, Video, Calibration, Mirrors, High speed cameras
This paper describes the contents of a unique introductory, applications oriented, high speed photography course offered to Imaging and Photographic Technology majors at the Rochester Institute of Technology. The course covers the theory and practice of photographic systems designed to permit analysis of events of very short duration. Included are operational characteristics of intermittent and rotating prism cameras, rotating mirror and drum cameras, synchronization systems and timing controls and high speed flash and stroboscopic systems, and high speed video recording. Students gain basic experience not only in the use of fundamental equipment but also in proper planning, set-up and introductory data reduction techniques through a series of practical experiments.
The end of the cold war and the drastic downsizing of missile research along with the steady retirement of personnel versed in the technical aspects of missile performance evaluation through photographic processes have created a situation where the number of qualified individuals to provide such services is precariously low and where the technology itself is being forgotten. At the Imaging and Photographic Technology Department at the Rochester Institute of Technology we are making a small effort to teach introductory concepts often taken directly from imaging technologies associated with missile range photography. These technologies involve near-miss analysis and basic photogrammetry, streak photography for measurements of velocity, acceleration and event duration, shadowgraph and schlieren imaging, high speed flash photography of explosive events, etc. One of the methods by which a healthy dose of respect for traditional technology is taught is by setting up a mock missile range in the Department's High Speed laboratory. This project includes a missile firing control station, a photography section, a missile assembly area and other interdependent activities. Students build their own rockets, are taught the fundamental principles related to synchroballistic photography, they become range 'officers' and are never in charge of launching their own rocket and acquiring their own data but have to depend on their classmates to perform their assigned roles without error. Eventually the students then analyze the film data and report on the performance characteristics of their missiles. It is the purpose of this paper to share with professional technologists one project that is part of the Imaging and Photographic Technology curriculum at RIT designed to help preserve the technologies which provide the foundation upon which SPIE itself was founded.
The potential of the high speed electronic flash and the stroboscope to significantly contribute to the fields of science and technology cannot be overemphasized. Important applications for these instruments and applied techniques have been described by Dr. Harold Edgerton and elaborated upon by numerous other workers. This paper presents a summary of some of these projects. They are presented here to not only gratefully acknowledge the direct connection to Dr. Edgerton's pioneering work but also to re-emphasize the usefulness of specific electronic flash and stroboscopic analysis techniques.
The stress testing of latex condoms by an air burst procedure has been slow in
gaining industry acceptance because questions have been raised regarding the
influence of the test apparatus on the likelihood of breakage occurring where the
condom is attached to the inflation device. It was desired to locate the areas at
which the condoms tend to burst and thus corroborate or disprove these claims.
Several factors associated with the bursting condom demanded the use of special
instrumentation to detect arid study the burst initiation process. Microsecond
duration electronic flashes were used for the initial stages of the investigation.
Although the absolute point of initiation of a given burst could not be photographed,
these high speed studies tend to indicate that the most likely place for high quality
condoms to break is not where they are attached to the inflation device but at an
intermediate area between the base and the tip of the condom. In addition, tear
propagation characteristics and velocities were determined with a delayed-flash
technique, a double-slit strip method and a rotating drum framing camera.
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