The shutter speed is intricately
linked to movement. The photographer can use it to show action,
or stop it, in a photo. As such, it serves as a creative
tool, which when well-controlled can help capture memorable
images.
Low Shutter Speeds:
In a stable environment, most people are able to hold a camera steadily
enough to avoid camera shake at speeds as low as 1/60 sec. Using a support,
or bracing properly, with the elbows tucked at the side, some can capture
sharp images with shutter speeds as low as 1/15 sec. Generally though,
at shutter speeds below 1/30 sec., a tripod becomes necessary to ensure
that camera shake won't interfere with the image.
High Shutter Speeds:
High shutter speeds are considered to be 1/250 sec. and faster. At this
speed and beyond, the possibility of camera shake is avoided altogether
and most motion can be stopped. Fast shutter speeds often require a bright,
or fast lens, a lens capable of wide apertures (low f numbers
such as f1.4 ~ f2.8). The larger apertures allow faster shutter speeds
when the ambient light is not at its brightest.
While low shutter speeds are prone to camera shake imparted by the photographer;
high shutter speeds are prone to missing the subject altogether as it crosses
the field of view of the lens, caused by the too slow reaction of the photographer.
To remedy this problem, the technique of looking through the viewfinder
with one eye while the other remains open can help. The eye looking through
the viewfinder sees the field of view while the other one provides the
peripheral vision necessary to allow taking the photo at the right time.
The importance of the direction of movement:
High shutter speeds are necessary
to freeze fast movement, such as a spinning wheel, falling
objects, birds in flight, etc. The shutter speed needed to
freeze movement is dependent on the direction the subject
is moving in, in relation to the camera.
A subject moving across the frame will require a faster shutter speed than
one moving obliquely across the frame. For example, if 1/1000 sec. will
freeze a subject travelling across the frame, 1/350 sec. can be sufficient
to freeze a subject moving obliquely.
The impact of the direction of
travel on the shutter speed is highlighted by the examples
shown below. A passing car is photographed from approximately
the same distance, and at the same shutter speeds.
Oblique motion:
1
2
Shutter Speed: 1/350 sec.
Shutter Speed: 1/45 sec.
Perpendicular motion:
3
4
Shutter Speed: 1/350 sec.
Shutter Speed: 1/45 sec.
5
Note the wheels
of the car are frozen at 1/350 sec. when coming at an oblique (1),
but still moving when the car is passing perpendicular to
the photographer (3). Similarly, at 1/45 sec. the
car is less blurred in the oblique photo (2) than
in (4).
In the last photo, (5) the same photo is captured at an even higher
shutter speed and freezes the wheels of the car completely.
Shutter Speed: 1/1000 sec.
Panning
Panning is a technique that requires
the photographer to follow the subject by holding the camera
steadily pointed at the subject, while rotating at the waist
to follow the movement.
Panning produces a clear subject against an effectively blurred background,
helping make the subject stand out even better. The technique is often
employed in automobile brochures as it imparts a feeling of speed, power
and excitement.
Shutter speed 1/45 sec.
Following or Leading
Following and leading are techniques similar to panning, as it blurs the
background while keeping a fast moving subject clear.
In this example the subject is followed by the photographer in a car behind.
The stationary trees appear blurred by the motion, but the car is clearly
defined.
Shutter speed 1/45 sec.
The shutter speeds required for some common subjects
A running dog, particularly
when it is running towards the camera, can be captured with
a lower shutter speed, such as 1/350 sec. But to guarantee
that all movement will be frozen, 1/1000 sec. will be better.
In general, with moving animals, the highest possible shutter speed should
be used, and keeping both eyes open will help in framing the subject properly.
Similarly, stopping the propellers
of an plane passing overhead will require a shutter speed
of 1/1000 sec. or higher; as will capturing a bird taking
flight.
Controlling movement
For many fast moving subjects
though, the image can sometimes be made more effective if
a balance is struck between freezing the action and allowing
a feeling of motion to remain.
In the example at right, the shutter speed used is 1/250 sec. This speed
is sufficient to freeze the water around the duck and the duck's body and
head; however, its rapidly flapping wings blur giving a sensation of the
bird's activity.
Photographing Water
Photos of water often present a different problem. A fountain serves as
an example in the photos below. Arresting a flow of water will usually
demand that a large aperture and a high shutter speed be used. The drawback
is of course that the depth of field will be shallow and that much of the
fountain may be out of focus.
In the example below, the images have been cropped to highlight the effects.
The image on the left uses a high shutter speed to freeze the movement
of the water. The image on the right uses a small aperture and a slower
shutter speed to provide a greater depth of field and define the cement
edge of the fountain clearly.
Above:
shutter speed: 1/1500 sec. at f8
Below:
a small section presented at full scale.
Above:
shutter speed: 1/250 sec. at f22
Below:
a small section presented at full scale.
Bubbles in the water are more distinct, and water droplets
are frozen in the air. The larger aperture required to have
a high shutter speed also limits the depth of field, and
the background is indistinct.
The bubbles are less distinct and droplets of water have
not been imaged. But, the use of a smaller aperture has increased
the depth of field, and the cement is clear.
A final note:
When photographing fast moving subjects it is easier to use a lens, or
zoom position, with a wider field of view than a telephoto. The wider field
allows more frame area for the subject to traverse and therefore more time
to take the photo. Cropping the image can then be used to get the desired
proportions.
Using shutter speeds to achieve a specific effect takes a bit of practice,
in an of itself an enjoyable pursuit. And, of course, with a digital camera
the results can be observed immediately and the techniques adjusted until
the results are those desired.
