Application of a photogrammetric technique to golf club evaluation

Photogrammetry is a technique used in many fields of engineering science. Its application usually requires sophisticated and expensive equipment and, sometimes, for engineering work, a complex illumination system. This paper describes the development of a technique applied to the measurements of the swing and impact of a golf club and ball, in which the requirements were inexpensive cameras, able to be placed in a wide variety of locations around the golfer, and using standard strobes and flash guns. The accuracy of marker location on the golf club is shown to be perfectly adequate if the correct distribution of control points is chosen. Application of the technique to the evaluation of the dynamic performance of composite shafts for irons produced surprising results contrary to the accepted and intuitive wisdom. Dynamic measurements of the flex and bend point location do not correlate well with the results from the standard static tests, which therefore appear to be redundant for the evaluation of shaft performance. The principal bend in the shafts tested is normal to the swing plane and of such magnitude that toe hits would inevitably occur unless the golfer compensates.