When I teach courses and workshops, one of the first things students want to know is how to freeze action. Whether it’s the kids running in the back yard, the dog jumping off the dock at the cottage or sports action on the playing field, action is one of the big things people want to photograph.
Freezing the action is quite simple – you need to use a “high” shutter speed. But this just brings up more questions. Like:
- What’s a shutter speed?
- What’s “high”?
- How do I make my camera do that?
1. Because your camera is sensitive to light, the inside of the camera is pitch dark most of the time. You only want light in there at the moment you want to take a picture. This moment is controlled by the shutter. When you press the shutter release button on your camera, a “curtain” opens to let light in and then closes to stop the light from entering. The amount of time this curtain stays open is called the shutter speed. Shutter speeds can range from 30 seconds or more to tiny fractions of a second, like 1/1000th of a second.
2. A shutter speed that stays open a long time is called a “slow” or “low” shutter speed. Conversely, a shutter speed that is open for a only a fraction of a second is called a “high” or “fast” shutter speed. Usually a practical dividing line between slow and fast is 1/60th of a second – anything higher is “fast” – anything lower is “slow”.
To freeze action, you need to use a shutter speed that is high – relative to how fast the subject of your photo is moving. For someone walking along the sidewalk, 1/125th would be fast enough. But for a horse galloping at 30 km/hr, a shutter speed of 1/1000th of a second might be necessary to “freeze the action”.
Notice how in this example all of the water spray is frozen in sharp detail. The shutter speed would have been at least 1/1000th of a second to stop that motion.
3. So, how do you make your camera use a high shutter speed. Many newer digital cameras have some preset “programs” that you can quickly use to capture typical photos. Look on your camera and see if you have a “Sports” program (it usually looks like a little running figure).
This will force the camera to use the highest possible shutter speed given the lighting conditions where you are shooting.
You can also set your camera to “Shutter Priority”. Most digital SLR cameras have a dial to set this. Look for the letters PSAM (or PTAM on Canon cameras). By setting the selector to S (or T on Canons), you can then set the shutter speed to what you want and the camera will set the aperture. If there is not enough light to use the shutter speed you want, you will need to increase the ISO setting to make your camera more sensitive to light.
