What is Shutter Speed?
Shutter speed is a photography term that indicates the length of time the shutter is open to allow light exposure to the film or image sensor. Used in conjunction with aperture size (f-stops), shutter speed determines total exposure and can be changed to create different effects. Shutter speed is measured in seconds, typically fractions of seconds.
Shutter speed is adjusted automatically when a camera is being used in automatic mode. However, shutter speed can be adjusted manually on most SLR film and digital cameras. Conditions that typically account for determining shutter speed include lighting and movement. A slower shutter speed is used in low lighting, while a short, or quick, shutter speed is typically used to capture moving objects. To create dramatic effects, such as intentional blurring or other artistic effects, the shutter speed may be adjusted to atypical speeds for the given conditions.
The shutter speed of most cameras can be adjusted in increments from 1 second to 1/1000 of a second, but longer and shorter exposure times can be achieved on some cameras. There are some rules of thumb for setting shutter speed, such as slower settings in low light and quicker settings for fast-moving subjects, but determining shutter speed for the desired effects is more a matter of trial and error.
To adjust shutter speed, you must first set your camera to a manual setting. Most cameras today will have a digital display viewable on the screen in the viewfinder. Most displays omit the 1 and display only the denominator of the fraction. For example, a shutter speed of 1/125 will be displayed as 125, while 1/500 will be displayed as 500 on screen. A setting of 125 is slower than a setting of 500.
While adjusting the shutter speed in various conditions and for various subjects will change the overall effect of the image, experimenting with apertures and sensitivity (ISO) along with shutter speed settings is essential to understanding the full impact specific settings can have on the overall photograph.
Written by J. Beam
