In activities such as running, jumping, throwing and kicking, it is the most distal body segments, the hands and feet, which move the quickest. A shutter speed should be selected that is sufficient to provide a non-blurred image of the fastest moving body segments. The choice of shutter speed depends on the type of activity being recorded. For slow movements, such as a grande plié in ballet or walking, shutter speeds of 1/150–1/250 of a second should be adequate; for moderately fast activities, such as running or a swimming start, shutter speeds of 1/350–1/750 of a second are more appropriate; for fast activities such as a golf swing or a tennis serve, a shutter speed of 1/1000 of a second or above may be needed.
Ensure correct lighting of the performer
If filming indoors, floodlights are often needed to achieve the required lighting level. Bartlett, 1997a, suggests that one floodlight positioned perpendicular to the plane of performance, and one to each side at around 30˚ to the plane, should provide adequate illumination. Filming outdoors in natural daylight is often preferable to filming under artificial lights, but natural light levels are inevitably less predictable. When filming in direct sunlight, the position of the sun will restrict where the camera can be located
Select an appropriate frame rate
Standard PAL video cameras have a fixed frame rate of 25 Hz, although this can effectively be doubled, provided the camera uses the interlaced scan method. Most high-speed cameras have adjustable frame rates. The frame rate used will depend on the frequency content of the movement being analysed, and the dependent variables being studied. Sampling Theorum (see Chapter 7 for more detail) states that the sampling frequency (frame rate) must be at least double that of the highest frequency present in the activity itself.
Read more about: bolly4u