The precise choice of shutter speed may
not at first glance seem to be of great importance to the landscape
photographer. The land itself is a static subject, literally as steady
as a rock, but nevertheless, shutter speed provides a valuable and
versatile control over the appearance of those parts of the subject
that are not firmly anchored to the earth.
In fact, the list is quite long: most
small plants move in a slight breeze, and whole trees sway in stronger
wind. Fields of crops form swirling patterns as the wind chases across
them, and smoke or clouds drift quickly across the sky on even quite
still days. All these subjects look quite different depending on
whether you picture them with slow or fast shutter speeds, but the
landscape subject that is most profoundly affected by shutter speed is
water. Moving water can take on a multitude of disguises, turning from
cotton-wool soft at a two-second exposure, to frozen crystal at 1/1000
sec or faster.
Man-made objects move, too, leaving
trails across your picture if you leave the shutter open for long
enough. Aircraft and cars leave behind straight traces from their
Choosing a fast shutter speed to freeze
an active landscape usually creates few problems: set a fast speed
using your camera's aperture-priority mode, or with the camera on
"manual". You'll probably need to select a wide aperture and low ISO or
fast film unless the light is bright.
To blur moving objects you must use
shutter speeds so slow that you can't handhold the camera, so use a
tripod or another support.
Slowing the Shutter
In sunlight, the slowest shutter speed you can use with the lens set to
minimum aperture is likely to be around 1/30 sec - faster if you using
film camera with sensitive film - and this isn't slow enough to get the
full effect of blurred moving water. If you want a softer image, you'll
need to fit a neutral density (ND) filter that cuts down the amount of
light reaching the film. The most suitable filter has a density of 2.0,
and cuts down the light reaching the film by 99%. This filter lets you
set a shutter speed nearly seven stops slower, so that in sunlight you
can use an exposure measured in seconds, not fractions.