Digital Camera Aperture
Settings
By: Jill Kane
A
great photograph depends on a lot of things. A great
view, a good camera, good light and of course,
aperture settings and shutter speeds. What exactly
does the aperture do? It is, basically, an aperture
or an opening. The size determines how much light
enters the camera through this opening and falls on
the image sensor to form the digital photograph. Did
too much light get through? Your photograph could be
a washout. Was it too little? You'll get a dark
picture.
Apertures come in different sizes - all
classified as 'f' numbers. Each number lets in
double the amount of light as the previous one. The
standard is between f/1.8 and f/16. The smaller the
aperture, the less light that will be let in. So an
f/16 lens will let in half the amount of light as an
f/8 lens. The aperture works in conjunction with the
shutter as well when it comes to the amount of light
let in. The speed at which the shutter opens and
shuts is also a factor that determines the amount of
light. When it comes to fast-paced action, a fast
shutter speed is essential to capture the motion.
For a landscape or a posed photograph a slower
shutter speed is fine.
A photographer who is extremely particular will
adjust both the aperture as well as the shutter
speed. A perfect balance between the two could very
often bring about that one perfect picture. It needs
a trained eye in order to judge perfectly exactly
what the settings should be. What he would also take
into account is the depth of field, that is, how
much of the image remains in focus. In larger
apertures, there is just a short range that is in
focus, whereas smaller apertures have a much deeper
range, going from the foreground close by to way
back, deep into the background. It would all depend
on the kind of shot to determine what the settings
should be. For those of us who do not have the
inclination, the understanding or the patience, we
can always resort to the automatic setting. It's
simple, the camera does all the work of adjusting
for you and you get a good photograph. It might not
be a work of art as might a photograph that a true
professional photographer might have taken, but most
cameras today give you a very acceptable quality.
Why do we need aperture settings at all? The simple,
old cameras didn't have any. If you choose a camera
with aperture settings like a telephoto, wide-angle
and maximum aperture features, you know that even in
an automatic setting, you will get different kinds
of pictures, not the same, flat look. It gives you
the freedom to take any kind of shot, anywhere, in
any light. Otherwise you might find yourself
restricted to typical, posed cheesy pictures without
too much character or depth.
(original) Aperture
Digital photographs are the result of light hitting
the image sensor. Too much light and the photograph
will be washed out. Too little light and the
photograph will be too dark. The shutter determines
how much light enters the camera, and there are two
settings which are related to the shutter --
aperture and shutter speed.
Aperture is the size of the opening between the lens
and the image sensor. Large apertures allow more
light to enter the camera than small apertures.
Apertures are expressed in 'f' numbers -- the higher
the number the smaller the aperture. Standard lenses
are usually rated between f/1.8 and f/16.
Each f-number allows twice as much light to enter
the camera as the previous f-number. For example,
f/8 produces an exposure which is twice as bright as
f/16.
Aperture
settings have two basic effects -- the amount of
light which strikes the image sensor, and the 'depth
of field'. Depth of field refers to the length of
the image which is in focus. Large aperture settings
have a shallow depth of field -- this means that the
focus of an image is relatively short which causes
foreground and background objects to appear out of
focus. Small apertures have a deep depth of field --
almost all the objects (foreground and background)
will remain in focus.
Aperture is directly related to shutter speed for
determining the amount of light that enters a
camera. Large apertures combined with fast shutter
speeds let in the same amount of light as small
apertures combined with slow shutter speeds.
Determining which combination is best for a
particular situation requires photographic judgment
that comes with experience.
To make it easier, most cameras have an automatic
setting which will do the calculations for you. Many
photographers, however, wish to control aperture and
shutter speed for artistic effect.
Since a large aperture can be used in conjunction
with a fast shutter speed, this is often a good
combination for action shots because the fast
shutter speed will 'freeze' the motion with a
minimum of blurring. Large apertures can also be
used for low light conditions where there is very
little movement in the scene. In this situation you
would combine the large aperture with a slow shutter
speed.
Simple point-and-shoot cameras usually have a fixed
aperture, and it is only with more expensive models
that you have adjustable aperture settings. When
choosing a digital camera, one consideration should
be the aperture range. There are several ways this
can be expressed in the camera specifications:
maximum aperture, aperture range, maximum wide-angle
and maximum telephoto apertures.
It is more useful to know the aperture range of a
particular camera rather than the maximum apertures.
A larger range gives you more flexibility in the
kinds of shots you can take. A good range for
all-purpose photography is from f/1.8 to f/16.
Each lens has its own aperture rating. Telephoto
lenses typically have a shallower aperture range
than wide-angle lenses because longer lenses need
proportionally more light. This is because they are
gathering light from a smaller source, so larger
apertures are needed to produce f-numbers which are
consistent with shorter lenses.
About the Author
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