Photography Basics: Understanding Shutter Speed

There are three basic elements to capturing good photographs: shutter speed, aperture and ISO (film speed). In this article, we will explore the basics of shutter speed and how to use this element to improve your digital photography. Whether you are a photography novice or just use a point-and-shoot digital camera, understanding how shutter speed affects your photographs will help you produce better images.

Shutter speed refers to the amount of time the camera's shutter is open, allowing light to hit the film (or the modern version of film, the digital sensors). The shutter is a panel of incredibly thin, overlapping leaves which fold back to expose a square of film (or the digital sensors) to the light reflecting back from the subject. You may change the shutter speed, how long those leaves stay open, anywhere from 1/2000 of a second to several seconds at a time.

If you are photographing outside in direct sunlight, there is a ton of light ready to race through the shutter and flood your film. In this case you would use a shutter speed of 1/1000 or higher. With this much light, it only takes a millisecond for the film to record the image. If you left the shutter open too long the picture would be all white, or burned/washed out.

If you are photographing in a low-light situation, like indoors or at night, it will take the small amount of light longer to reach the film and record an image. In these cases you use a longer shutter speed, such as 1/20 or 1/10.

You know those awesome photographs of lightening over the beach? Usually, the photographer leaves his shutter on the "Bulb" setting to take those. When the camera is set on Bulb, the shutter remains open as long as the photographer holds down the shutter button (the main button that triggers the photograph). To avoid camera shake, skyline photographers will set their cameras on a remote and leave their shutters open for twenty minutes or more to capture several streaks of lightening.

There is more to using shutter speed than just available light. Since shutter speed is the amount of time the film is open and exposed, it affects what kind of image you can capture. Let's go back to the lightening photographs. The shutter is left open on the Bulb setting for twenty minutes. Only a few streaks of lightening strike in the exposed area during that time. However, since the film is being exposed for that entire time, the photograph shows all the lightening strikes in one frame. By the same concept, if you use a long shutter speed and your subject moves, the image will show the blur of movement.

Let's say you are photographing an Olympic skier. You take the first image at 1/30 shutter speed. The background may be completely in focus, but the skier will be a blur as he moves through the frame. You take the second photo at 1/2000, so the frame captures only half a millisecond of the action. The skier didn't have time to move far in the frame while the shutter was open, so you effectively capture a crisp motion shot.

Just as when your subject moves on a low shutter speed, your photograph can also record blurs from camera shake. Camera shake is when the camera moves enough while the shutter is open to blur the photograph. If you are hand holding your camera on 1/30 shutter speed, your hands will naturally shake enough to make the photograph soft and un-focused. On slower shutter speeds, even if you are braced, your heartbeat can shake your body enough to move the camera. In these cases a tripod is an absolute necessity.

However, most people rely on their camera's automatic mode to do all the work. They like to just point and shoot without learning everything about photography. So how can shutter speed help their photographs if they use automatic anyway?

An automatic camera generally uses 1/60 or 1/100 depending on the light conditions. By understanding how shutter speed works you will have more creative control over your photographs, even when using automatic scene modes.

One option many digital cameras offer is shutter speed priority mode. In this mode, you tell the camera what you want the shutter speed to be while your camera sets the correct aperture to get a good exposure. This is good if you know you want a certain effect. Maybe you're shooting sports and you definitely want the pitcher to be frozen n action. Use shutter speed priority mode to set the shutter speed at 1/2000. As you shoot your photographs, the camera will adjust the aperture for a good picture, but keep your chosen shutter speed.This also work if you want to blur a subject for effect.

Understanding shutter speed also helps you understand how to use your scene modes. (Check out my article: www.associatedcontent.com/article/188063/your_digital_cameras_scene_modes_what.html)
When you set your camera's "Sports" mode it knows to use the fastest shutter spped possible. When you set the "Night" mode, the camera knows it needs to leave the shutter open several seconds to capture those stars or that lightening.