Video analysis of a golf swing

Casio recently developed a set of high-speed cameras. These cameras are actually still digital cameras, but they have the ability to capture high-speed video. The capture rates vary from 210 frames per second (fps) to 1200 fps. The price range is from $300 to $1000 per camera.

These cameras open exciting opportunities to explore science that is difficult to see at normal speed. Here are a couple of examples: Teachers want to collect motion data from fast-moving objects, such as the speed of a baseball as it leaves the pitcher’s hand, or the speed of a golf ball after being struck by a club. It would be natural to assume that a Motion Detector could help answers these questions, but these objects move too quickly for the Motion Detector; however, video analysis of these fast-moving objects offers a great solution. We measured the speed of a golf club and the speed of the golf ball after impact using a Casio EX-FH20. The figure above shows a frame from the video analysis, and the graph shows velocities of the club head and ball.


Movie options dialog box in Logger Pro 3.8.2

There is one, easily corrected, technical challenge in getting this data. During video analysis, Logger Pro gets the times associated with each frame from the time stamp that the camera puts on each movie frame. High-speed cameras are designed to replay the movies in slow motion, so instead of using the actual frame rate, for example 1000 fps, they use a 30 fps rate.

Logger Pro does not have the correct frame rate available; however it is easy to get the correct times. Simply double click the Movie to bring up the Movie Options dialog box. In the dialog box, click the “Overwrite the frame rate” button and enter the correct frame rate, 1000, in the box. (This feature is in Logger Pro version 3.8.2 or newer.)

Download the video and Logger Pro experiment file »

Logger Pro FAQs for video capture, display, synchronization, and analysis »