Tell the whole story
Canon's 10-22mm ultrawide, which I love), you can get some really cool effects with a unique visual perspective.
Catch the action
Of course, you can't have sports photography without photographing the sport itself. Sports like soccer which are played in bright sunlight lower the bar significantly, because it's no longer necessary to use expensive, wide-aperture lenses or camera bodies with awesome high-ISO noise levels. A high-end point & shoot camera with a good optical zoom can take surprisingly good shots of action that's not terribly far away from your seat.
It also helps immensely if you can get down to shoot from the level of the players. For little kids, that means kneeling down on the field so that your camera is at shoulder height for the kids. This perspective makes the viewer part of the action rather than a spectator in the stands.
My equipment choices
10-22mm zoom lens on my Canon 50D backup body, and store that (without a strap) in a small, triangle-shaped holster bag attached to my belt on my right hip. I whip out this camera when the action is right in front of me. Sometimes I hold the camera out at arm's length over the goal, shooting downward as the kids attempt to score. Other times, I'll shoot a worm's eye view of an in-bounds pass. It's also great for capturing crowd reactions. I might just as well duct tape this lens to the 10mm setting, since that's where I always use it. I frequently put a circular polarizer on this lens, since it will typically be capturing a fair amount of sky, and the polarizer will darken it up for much more drama.
When shooting on a clear or consistently overcast day, I set my exposure manually so that it doesn't change on me. On a partly cloudy day when the light is constantly coming & going, I shoot in Shutter Priority (Tv or Sp) mode, since freezing action (and camera shake) with a fast shutter is more important than getting a specific depth of field on these wide angle shots.
|Canon 7D autofocus points|
The focusing mode should be continuously focus as long as I've got the button pressed. Canon calls this "AI-SERVO." This allows me to track along with the players, keeping them in focus until I decided to take the shot.
For capturing action, I generally want to isolate my primary subject and blur out the foreground & background, which means using the widest aperture that your lens allows. For cheaper zoom lenses, this generally means f/5.6. If my lens has a variable aperture (as most inexpensive zooms do), I typically set the camera in Aperture Priority (Av) mode at the widest aperture (f/4, for example). As I zoom in and the aperture changes to f/5.6, the camera will automatically reduce the shutter speed to match. This method gives me both the tightest depth of field and the fastest shutter speed possible at any focal length. I try to keep the shutter speed no slower than 1/1000s if I can.
Which lens you choose depends on how big your playing field is and where you'll be sitting. If you're right on the sidelines of a tiny micro-soccer field, a 300mm lens (horizontally, on an APS-C sensor) will fill the frame with a pre-schooler's body at the far end of the field. If you're near the midfield line, a 200mm lens will do just fine. If you're shooting high-school sports from the sidelines, a 400mm lens (or a smaller lens with a teleconverter) would probably make you happier. As sexy as it might sound to use your 300/2.8 prime lens, you'll probably find it too limiting if you're positioned anywhere close to the field, since the action takes place all over. When shooting from the stands of a high school or college game, where even the closest action is a ways away, a prime lens would be more useful.
Canon 70-300mm f/4-5.6 lens last season, with great results. I've since purchased a Canon 70-200/2.8 lens, and will combine it with a 1.4x or 2x teleconverter next season. Even pre-schoolers move fast enough that image stabilization is a useless feature. If your lens has a focus limiting switch, use it. It speeds up your focus time by preventing the lens from hunting for a subject less than 10 feet from you.
If you only have one camera body, you'll still want to take a wider lens just in case, but don't be too cavalier about swapping lenses during the game, especially if there's much of a breeze. Dust on your sensor sucks. You should get a few wide shots now and then to set the stage, but you'll want to wear the long telephoto lens most of the time.
When positioning yourself, keep in mind where the light is coming from. Unless you're going for a creative silhouette, you'll want the sun at your back so it's lighting your subjects. Also be mindful of the background that will be in your shot. Do you want cheering fans as your backdrop? The goal? An unobtrusive, grassy berm? The parking lot? If you're rooting for a particular team, try to position yourself near their goal so that the players are facing you during most of the action. Of course, sometimes these considerations are mutually exclusive, so just do the best you can.
The hardest thing for me to learn when shooting sports was to keep the camera trained on the action all the time--even when not shooting--because you can't react fast enough to catch a great moment if the camera's hanging from your neck when it begins. When a great play is made, zoom out a little bit, but keep the camera to your eye & aimed at the major players so you can capture their celebrations. These moments make better memories than the kick that scored the goal. Likewise, keep the camera trained on the players any time they're not uncontested during normal play. Great plays will begin and end in a split second.
Speaking of split second reactions, I always set both cameras to rapid-fire at the fastest frame rate possible, which is 8 fps on my 7D. Don't be afraid to burn off 3-4 frames with every button press, as you never know which of those four will capture the greatest action or expression. You can always delete the bad ones later.