creative controls
Duration of exposure
All photographs are time exposures of shorter or longer duration, and each describes an
individually distinct parcel of time. The photographer, by choosing the length of exposure, is
capable of exploring moving subjects in a variety of ways.
By choosing long exposures moving objects will record as blurs. This effect is used to convey
the impression or feeling of motion. Although describing the feeling of the subject in motion
much of the information about the subject is sacrifi ced to effect. By selecting fast shutter speeds
photographers can freeze movement. We can see the nature of an object in motion, at a
particular moment in time, that the human eye is unable to isolate.
Fast shutter speeds
By freezing thin slices of time, it is possible to explore the beauty of form in motion. A fast shutter
speed may freeze a moving subject yet leave others still blurred. This is dependent on the speed of
the subject matter and the angle of movement in relation to the camera. For subject matter travelling
across the camera’s fi eld of view, relatively fast shutter speeds are required, compared to the shutter
speeds required to freeze the same subject travelling towards or away from the camera.
Limitations of equipment
Wide apertures in combination with bright ambient light and/or high ISO allows the use of fast
shutter speeds in order to freeze rapidly moving subject matter. Some telephoto and zoom lenses
only open up to f4 or f5.6. If used with a low ISO there is usually insuffi cient light to use the fastest
shutter speeds available on the camera.
Mark Galer