A photographic method for displacement/time recording
F M Bruce · British Journal of Applied Physics · 1950
Small spherical reflectors attached to or formed upon the surface of a moving body produce a point image of a fixed light source. This image moves with the body to which the reflector is attached, and by recording its motion on a continuous-feed or rotating drum camera, a displacement/time record is obtained in the form of a fine and sharply focused continuous line which is suitable for detailed analysis. Recording may be carried out under normal lighting conditions by this technique. The camera described gives time scales in the range 0 to 315 in/sec.