A photograph showing movement depicted as a continuous pattern of light. It is made by exposing a STILL film or plate for the period of the cycle of the activity being analysed. Electric light bulbs are attached to the hands, arms or feet of the subject, whose work is being analysed. The technique was first used in 1890 by Marley to study the movements of athletes and later developed by Gilbreth in the study of work.
This is a development of the cyclegraph where the electric light bulbs are made to flash on quickly and die away slowly. The path of light appears as a series of pear-shaped dots, the movement being in the direction in which the dots point. The spacing between the dots indicate the speed of movement and show accelleration and decelleration.
- Experiments were made with stereoscopic photography, in order to reproduce the effect of three dimensional movement - i.e. towards and away from the camera;
- Later colour film was introduced using different coloured bulbs for each of the two hands being analysed.
- A CHRONOGRAPHIC UNIT, which is a device (formerly battery operated) to light the bulbs and to enable the flashing to be varied between 10 and 25 flashes per second;
- Camera and exposure meter - a camera capable of double exposure will enable a normal picture of the scene to be superimposed over the chronocyclegraph;
- Supplementary lighting for use when taking the instantaneous exposure to obtain the superimposed picture.
- Set the frequency of flashes - depending on the type of job;
- Attach bulbs to hands;
- Decide the exposure time;
- Take a time exposure for the period of the job cycle whilst the operator performs the job - the location would be a darkened room in former times;
- Take a second, instantaneous exposure on the same film, if it is required to superimpose the scene on the chronocyclgraph.
Uses of Chronocyclegraphs
- Developing a better work place - chronocyclegraphs reveal obstructions and bad locations;
- Analysis of a complex movement;
- An aid to training;
- Comparison of two methods;
- Publicity and advertising;
- Design of new equipment.
Photographic Aids to Method Study
Both still and cine photography are used in cases where more detailed investigations are required and where the operations may be of a very short duration or performed at a high speed or where several different jobs are being carried out simultaneously;
- a permanent record is obtained of the work being carried out;
- the record can be referred to at any time
- the excellent means of demonstrating differences in methods is a valuable aid to training;
- reproduction of the original method is possible at any time;
- repeated study of an operator's activities can be made without further interference;
- examination of intermittent work can proceed when the work itself is not actually in progress.
Use of 'Cine' Films
- They can be projected at any required speed and can be stopped at any convenient point;
- They can be reversed, thus enabling clumsy or awkward movements to be easily detected;
- It is possible to concentrate on particular activities involved without being affected by the noise of normal surroundings.
Micro Motion Photography
Micro motion analysis is the critical examination of a SIMO CHART prepared by a frame by frame breakdown of a cine film of an operation; when a film is made for this purpose an exposure of 1000 frames per minute is usually employed.
Memo Motion Photography
This is a form of time lapse photography which records activity by a cine camera adapted to take pictures at longer intervals of time - e.g. one frame per second.
By employing this device it is possible to record the activities within the working area over a lengthy period. The resulting series of still shots can be analysed and used as a basis for the construction of appropriate charts and method improvements - e.g. team operations, several operators or several machines.