Sport and Action Photography, page 3: Shooting techniques

Frozen and Blurred Techniques

There are a variety of techniques that you can use to photograph action. These range from those designed to freeze a precise moment to those that give the feeling or sense of movement and those that are a combination of the two. Freezing the action is the ultimate aim for a lot of sports photographers, and there are essentially two techniques you can use to achieve this:

1. Fast shutter speed.
There is a direct link between aperture, shutter speed, ISO value and the light in the scene. Put simply, to be able to use speeds that will freeze motion, you need a fast lens, high ISO setting and good light.

2. Fast light source.
The alternative of shooting with a fast shutter speed is exposing with a light source that has a very short duration, like a portable flash. Most on-camera flash systems output light for durations of between 1/800 and 1/30,000sec. It is this brief flash that freezes the motion. Don’t be confused with the shutter speed your camera uses to sync with the flash – usually between 1/125 and 1/250 sec – the length of time that is used to expose your frame is based on the flash’s duration.

Using Slower Shutter Speeds
Photographers also like to use slower shutter speeds to capture moving subjects. The blurry results communicate a feeling of motion. The shutter speed, direction of the motion through the frame, the lens length and the speed of the subject all govern the amount of blur in the final image. Try a range of speeds with the same subject. Your tests will give you a starting point that you can use next time you are shooting a similar subject.

Panning and Flash Blur
An extended blurred motion technique is panning. This involves the photographer moving with the motion of the subject, keeping the subject in the frame during the exposure. When this technique is coupled with a slow shutter speed, it’s possible to produce photographs that have sharp subjects and blurred backgrounds. Try starting with speeds of 1/30th sec.

You can also combine stillness and movement, using a flash blur technique. To achieve this effect you need to set your camera on a slower than normal sync shutter speed. The short flash duration will freeze part of the action and the long shutter will provide a sense of motion.

Focusing Issues
In the viewfinder of a modern AF system you will see one, or more than one, focusing area. For the camera to focus accurately, the subject must be in this area. In entry-level cameras the area is positioned in the centre of the frame. In the viewfinders of more expensive examples you will not only find multiple focusing areas but you will also notice that they are distributed across the viewfinder. With the aid of a dial, or a thumb toggle, the photographer can choose which area will be used for primary focus. This enables the focusing of subjects that are off-centre.

Either manual or autofocus modes are suitable for action shots. There are a range of activities that allow the photographer the chance to predict where the subject will be with reasonable accuracy. A zone focusing technique is most useful for these occasions. To use this technique the photographer would pre-focus (in manual mode) on one point and wait for the subject to pass into this zone before pressing the shutter.

What about AF modes, though? Two AF modes are found on most cameras: single and constant auto focus. These determine the way the AF system works on your camera. In single mode when the button is held halfway down, the lens focuses on the main subject. If the user wishes to change the point of focus then they will need to remove their finger and repress the button. If the subject moves, while using this mode, then you must refocus.

The constant or continuous focusing mode also focuses on the subject when the shutter button is half pressed, but when the subject moves the camera will adjust the focusing in order to keep the subject sharp. This is sometimes called focus tracking. Some AF systems have taken this idea so far that they have ‘pre-emptive focusing’ features that not only track the subject but analyse its movement across the frame and try to predict where it will move to. This helps to keep the main subject fully sharp.

Each mode has its uses. Single focusing is handy if you wish to focus on a zone into which the subject will appear. Constant is more useful for subjects that move more randomly.

Continuous Shooting Mode
Many digital cameras have the option to shoot a rapid sequence of pictures. The rate at which sequential images are captured and the total number possible for a single burst varies.

If you plan to take action shots regularly, use the list below to compare the continuous modes before buying a new camera:

1. Check the frame rate (in frames per second)

2. Check the sustain rate. Look for how many frames can be shot at the fastest rate before slowing. Find out which file formats work with the fastest rates

3. Check the compression level used if the mode is only available in JPEG format. Low-compression images process faster but they have lessquality.

4. Look at the picture dimensions for each mode. For example, a very fast mode that produces pictures with only enough pixels to print a postage stamp isn’t that useful.

5. Check the type of memory card used for the statistics as the speed with which the card saves the files can affect the overall frame rate.