Your selected shutter speed controls not only the amount of light, but also the visible motion in your photograph. Slower shutter speeds will show any movement in the scene you're photographing as a blur. Faster shutter speeds will freeze that movement. The fastest shutter speeds will stop just about any movement, short of a speeding bullet.

Very Fast Shutter Speeds

1/8000th of a second is about as fast as you'll find in a camera. At 1/8000th of a second, virtually all movement will be frozen in place. It sounds really cool, but in practice you'll rarely ever use it.

For all but the most extreme situations, 1/2000th and 1/4000th of a second will give a similar look to 1/8000th. These speeds are very effective with high-speed motor sports. And 1/1000th of a second will freeze just about any action in human sports like football and soccer.

1/500th is on the bottom of the high speed range. If you're trying to freeze the action in sports or news events, don't go below 1/500th of a second.

Medium Range Shutter Speeds

Most photography is probably done with three general-purpose shutter speeds: 1/60th, 1/125th, and 1/250th. Working with these three shutter speeds will allow you to get a high-quality image in most daytime scenes.

If you are photographing people, you'll want to stay at 1/250th to freeze any possible motion. If you have to use 1/125th and 1/60th for people shots, take extra shots so that you're sure to have a few crisp images to choose from.

Slow Shutter Speeds

Slower shutter speeds are effective for a variety of situations, whether you're looking to show a little motion in your photographs or just need more light to allow for increased depth of field.

1/30th of a second is about the slowest most people can hand-hold a normal or wide angle lens without camera shake. But keep in mind that if you're shooting people, you will begin to pick up their motion at this speed and below.

Unless you are going for a creative blur or pan effect, you really should use a tripod below 1/30th of a second.

Ultra Slow Shutter Speeds

Professional cameras go down to shutter speeds as long as 30 seconds. And some models allow you to open the shutter for as long as you'd like, provided the battery doesn't run out. At these low speeds a tripod is a requirement for photographs of any clarity.

Flash Shutter Speeds

If you're shooting with a flash, there is often a limit to how fast your shutter speed can be set. Since the shutter and flash unit have to work in sync, even pro cameras will often only work up to 1/250th of a second with a flash unit.

Additionally, if your flash is your only light source, it works as the equivalent of using a fast shutter speed. The burst of light from your flash only lasts for a very brief fraction of a second and freezes action very effectively.