British Kinematography (1951)

84 Vol. 18, No. 3 THE FILM IN RESEARCH R. McV. Weston, M.A., F.R.P.S. (Member)* Read to the British Kinematograph Society on February 7, 1951 FROM the earliest days of scientific investigation, the research worker has pressed into his service all and any method or device which would enable him to make his measurements more accurately, make his observations more easily, or widen the scope of his physical senses. Equipment of this kind constitutes the tools of the research worker, and ranges from the simple pencil, ruler and paper, on the one hand, to the electron microscope, the 200-inch telescope, and the electronic calculating machine on the other. During the last hundred years, photography has been used by all kinds of research workers because of its obvious advantages, such as speed and freedom from human error. About 70 years ago, two independent workers, an Englishman and a Frenchman, interested in different branches of biological science involving movement, were at work on new photographic methods, and from these men — Muybridge and Marey — came the foundations of motion picture photography and the use of motion pictures in research.1 The motion picture is before the public mainly in its entertainment form, but the fact must not be overlooked that it was first conceived and produced, not to entertain and amuse mankind, but to widen the horizons of human knowledge and to facilitate serious scientific research. Value of the Film Let it first be asked, why it is that the film is such a valuable aid to the research worker? The reasons are not difficult to find, though they are not always fully appreci ated. They may be enumerated as follows 1. A detailed, accurate and permanent record can be made of almost any event. 2. The recording can be made automatic in operation, thus dispensing with a human ooserver. I. The method is applicable to almost any object that can be observed either with the unaided or the aided eye. 4. Most of the information in the record is readily available in visual form without interpretation or calculation. 5. 'lhere is no mechanical interference with the object under investigation. (3. Measurements of time, velocity and acceleration are easily obtained. 7. Alteration of camera speed alters the apparent speed of the event recorded. 8. Invisible radiations may be used, to which the eye is not sensitive. Other recording methods, for example, oscillographs and kymographs, fulfil some of the above functions, but no method, other than the motion picture, combines them all. It is not possible to say which of the above qualities is most useful to the research worker, as each problem will make different demands upon the motion-picture camera, but cases are frequently encountered in which no other recording method is suitable, or indeed possible. The measurements of time or acceleration and alteration of apparent speed are perhaps the most important from the scientific standpoint, because in these two groups we are concerned with actual measurements and with the observation of events outside the narrow range of speeds that can be appreciated by the eye, rather than with the mere recording of events. The alteration of apparent speed gives information which is not available by any other means. No other technique or recording method gives the same command over time that is available from the motion picture film. The above headings can now be considered in more detail, together with some actual examples. * Simpl, Ltd.