Coping with subject movement
Master shutter speed to shoot pin-sharp shots of fast action
There are three important points on the exposure triangle – aperture, ISO and shutter speed. Their relationship is tied closely together, but when it comes to shooting a subject that moves, shutter speed is the most important factor. If you want to capture pin-sharp shots of something moving, you need a faster shutter speed than you do for something that’s static.
Of course, the speed of moving objects varies, so you can use different shutter speeds and still get your subject in focus. For example, to capture a person walking you can get a sharp shot at 1/250 sec, while a person jogging will need at least 1/500 sec, and the same person running as fast as they can will probably be slightly blurred unless you increase shutter speed to 1/1000 sec or more. The faster your subject’s movement, the higher the shutter speed needs to be to freeze the motion.
It’s easy to get a fast shutter speed when the sun is out, but when the light isn’t as good, you need to get help from either aperture or ISO, or possibly both.
Opening up the aperture lets more light in, although it will also decrease depth of field. Increasing ISO will make the sensor more sensitive to light, so higher shutter speeds can be achieved – though to the detriment of quality, as the more you push up ISO, the more you increase the noise in the picture.
Ultimately, if you want to freeze the motion in a photograph, there is no such thing as a shutter speed that’s too slow, since the appearance of a mountain biker suspended in mid-air, for example, is pretty much the same at 1/2000 sec as it is at 1/5000 sec.