Graphics Reference
In-Depth Information
(a)
(b)
FIG 7.23
Choosing the right shutter
speed is important. a: A relatively
slow shutter speed has resulted in
motion blur. b: A faster shutter speed
has allowed the detail of the wing to
be captured.
speeds that can be of an almost indefinite length; this may be very useful for
photographing subjects in very low light conditions, but such long exposure
times may not be of particular use when you're trying to capture action. Short
exposures are achieved by fast shutter speeds up to 1/2000th of a second.
Such high shutter speeds are critical for capturing actions. The faster the
action, the faster the shutter speeds you'll need.
In addition to the duration and intensity of light, we have already seen how
the sensitivity of the film or the digital sensor also plays its part in determining
the amount of light required to achieve a correctly exposed image.
Depth of Field
Depth of field
refers to the distance that extends in front of and behind a
chosen subject, which remains sharp and in focus. A really deep depth of field
may extend a great distance, from a few meters away from the camera all the
way to the horizon. A very shallow depth of field may extend over only a few
millimeters. A shallow depth of field can be used in a very creative manner for
the purposes of capturing images as part of your research into action analysis,
but a greater depth of field can provide images of a subject that is in focus in
its entirety. Fully sharp images from front to back should at least allow for a
more thorough analysis of your subject.
FIG 7.24
The appropriate depth of
field (sometimes shallow, sometimes
deep) may make the analysis of action
easier.
