Let There Be Light
Taking a picture in its simplest form means exposing the film to light. Two different devices — the shutter and the aperture — work together to determine how much light enters the camera and hits the light-sensitive surface.
The shutter controls the length of time that light is allowed to expose the light-sensitive surface. On modern SLR cameras, shutter speeds are usually indicated on a display panel or a shutter-speed control dial. Some older SLRs have a shutter speed control ring on their lenses, which you turn to select the speed.
Shutter speeds are measured in fractions of a second — a shutter speed of 125 means 1/125th of a second. Typical shutter speeds range from 1 second to 1/1000th of a second.
The higher the number, the faster the shutter opens and closes. Shutter speeds also allow precise control over how long light enters the camera. A speed of 1/125 will let light in for 1/125th of a second.
When working with shutter speeds, keep in mind that slow speeds — those of 1/30th of a second and longer — will require you to use a tripod or another very sturdy support. Slower speeds will capture every tiny movement the camera makes, so the camera must be held as still as possible. Some people with very steady hands might be able to take handheld pictures at 1/15th of a second, especially when shooting with a normal or wide-angle lens. Getting a steady shot with a zoom or telephoto at this shutter speed, however, would be nearly impossible.
The following list outlines the best shutter speeds for certain conditions:
B (Bulb). Best for taking pictures at night when you need long exposures. Keeps the shutter open for as long as the shutter release button is held down. Must use a tripod or other sturdy support.
1 second, ½ second. Best for shooting at night and some dim lighting situations using narrow aperture settings. Good for photographing objects. Must use a tripod or other sturdy support.
1/8 second. Good at letting in enough light when needed for small apertures in low light situations. Must use a tripod or other sturdy support.
1/15 second. Taking pictures in existing light when using small apertures. Tripod or other camera support is recommended to avoid camera shake.
1/30 second. Another good shutter speed for existing-light pictures. Slowest shutter speed recommended for handheld photography.
1/60 second. Outdoor photography in overcast conditions and on brighter days when using a narrow aperture. Better than 1/30 for eliminating camera motion.
1/125 second. Outdoor photography under bright light with wider apertures. Good for capturing moderate action. Also a good speed for using short telephoto or moderate zoom lenses.
1/250 second. Outdoor photography with good light and wider apertures. Lets you capture faster action. Slowest shutter speed for hand-held telephoto sports shots.
1/500 second. Even faster action shots. Needs good light and wide apertures. Good shutter speed for fast-action photography with a long lens.
Once you get above 1/500 of a second, you'll be able to shoot even faster action. However, these shutter speeds require a lot of light or very wide apertures, which result in extremely shallow depth of focus.
