Historical Aspects and Current Trends in Cinematography

  • J. Wolf

Abstract

The quantitative analysis of human motion identifies parameters of the observable aspect of the movement and further deals with the cause-effect relationship. Once the initiating and regulating mechanisms are understood sufficiently, conclusions regarding the dominant aims of performance and load optimisation can be drawn. Motion is the displacement of bodies in time. Hence the descriptive kinematic analysis measures location and/or time. Further parameters can then be deducted. This requires in some cases additional information such as anthropometric data. Kinematic data are in general obtained by having fixed locations and measuring time (photoelectric cells, contact mats, ultrasound sensors) or by having constant time intervals and the registration of the change of location. The aim of the research is critical .for the choice between time and location variability and hence the technique and quality. Quality of the measurement depends on the spatial and temporal resolution as we11 as the dimensionality. Optical techniques have decisive advantages regarding the criteria spatial resolution and dimensionality. Therefore they are widely used for technique oriented two or three dimensional analysis of the CM and segment motion. In the past kinematic techniques have been classified based on the technical criteria. However it appears to be more practical for the user to structure based on resolution and dimensionality i.e. the measurement quality. This structure is also supported by the common mathematical and theoretical fundamentals of all optical techniques. The importance of optical methods for the analysis of motion has been acknowledged since the end of the 19th century. The basic model for perspective projection was known for a long time. Several approaches were attempted to ensure temporal synchronisation of at least two cameras which is one prerequisite for 3-d analysis. The same holds true for the integration of the one or two dimensional pan and zoom which are prerequisite for measurement quality (adequate spatial resolution) when analysing motion in large object spaces. The paper will combine historical and present trends of cinematography to propose a structure based on measurement quality i.e. temporal and spatial resolution as well as dimensionality. This will also show the common mathematical and theoretical principles.