Author: Wendy
Folse
First published on: July 1, 2001
Isolating the Subject
One of the most
important points to consider in composition is isolating
the subject so that it becomes apparent to the viewer
what the photographer is trying to show. There are many
ways to isolate the subject and in this article, we will
cover three of them, framing the subject, selective
focus, and depth
of field.The main purpose for isolating the
subject is to make it stand out from the background and
to direct the viewer's eye to the center of attention,
not necessarily the center of the photo.
In the portrait of the young girl, the eyes are the
center of focus and the hat, leaves, and even her hair
help to frame her face which is the center of attention.
Framing the subject
The first choice in
deciding how to frame the subject in the viewfinder is
to decide whether you want a horizontal or vertical
composition. In a previous article we discussed the
merits of both. The choice is up to the photographer,
but ultimately the frame choice should compliment the
subject. A skyline looks best in horizontal, while a
single tall building looks best in a vertical.
The next consideration is where we get a little more
creativeand where we start to make choices, that brings
our photography to a new level. This step requires us to
think a little and to scout around for things that we
can use to frame our subject in order to direct the
viewers eye towards the main point of interest. Framing
devices help to keep the subject contained within the
photo.
A photographer's choice is limited only by his
imagination and skill when choosing a framing element.
Maybe it is a palm tree in the foreground that
gracefully wraps around the beach in the distance.
Perhaps, it is the outline of a window that the viewer
looks through to the fields beyond. Nothing says, "we're
at a football game" like a shot of the crowd framed by
the upright goal post. Or how about the often overused
classic of a bride looking at her reflection in a
mirror. This is a technique called a frame within a
frame.
Even a bare white
wall can frame the subject by isolating it when the only
element surrounding the subject is the white wall. This
is the same concept as a photographer using a backdrop.
The purpose for the backdrop is to in a way frame the
subject with a continuous pattern, color, or tone.
Patterns are often used as framing devices to help
contain the subject within the photo. Look around you
and see what elements are present that may lend
themselves to this technique. In the picture here, the
iron mesh of the gates serve as a frame.
Depth of field can also be used as a framing device
to isolate the subject. Using a very shallow depth of
field can blur the background creating a frame that
surrounds the subject.
Another consideration is the eventual framing of the
photo itself. Be careful not to place parts of the
composition so close to the edge of the viewfinder that
they will be cutoff either during printing or when
matting and framing.
Selective focus
This technique relies on
the creative use of depth of field and 
a large aperture
to direct the emphasis on the subject by deliberately
placing surrounding elements out of focus. Sometimes the
foreground maybe placed out of focus in order to frame a
distant subject. Often the background will be placed out
of focus in order to emphasize a foreground element. The
idea is to use what is in-focus and what is out of focus
as a tool for isolating the subject. Again with this
technique as with others, it is limited only by the
photographer's imagination and creativity.
In order to use selective focus effectively you must
first learn to understand depth of field and how to
control it. In a future article we will be covering
depth
of field to a greater extent. For now, it helps
to gain a basis for what it is and what it does.
Depth of Field
The term is used to
describe the amount of distance in a photograph that is
in sharp focus. Sometimes it is easier to think of depth
of field as an imaginary plane that crosses the "field"
of the photo from front to back. The further back or
depth of the plane, than the more that will be in focus.
The size of the aperture controls the depth of field. At
very small apertures such as f/22, the plane covers all
subjects and all are in sharp focus. When we use a very
large aperture such as f/2, then there is a very limited
depth of field and only the exact focusing point maybe
sharp while everything else is blurry.
When working with very large apertures it becomes
critical to pick out a focal point and center the
focusing on this spot in the viewfinder. As three
dimensional objects do not occupy one plane, the
photographer must keep in mind which part of the object
is critical and adjust the focus on this point. This is
where a depth of field preview button on an slr comes in
handy. If your camera doesn't have one then your task is
to think about the amount of focus necessary to
represent the object according to your chosen theme.
What are you trying to show and how critical is it.
Remember that what you see is not necessarily what you
get when working with larger apertures. The amount of
blur may not be apparent in the viewfinder even with a
depth of field preview.
The distance at
which you focus on an object also controls the amount of
depth of field. The farther away you focus, the larger
the depth of field. The closer in you focus, the
shallower the depth of field. There is a rule of thumb
that says that from the focal point you have about
one-third of the distance in front of the focal point
and two-thirds of the distance behind the focal point.
When shooting landscapes at small apertures this factor
is not critical because everything will be reasonably
sharp. However, when working with smaller objects at
closer distances and using larger apertures, this does
become very critical. It helps to remember that a
photograph is a one-dimensional representation of a
three-dimensional scene.
For example, say that you wish to take a close-up
portrait of a person and you want to blur the
background. After you work out the correct lighting, you
decide you need a relatively larger aperture in order to
blur the background but you don't want the face to be
blurry either. What do you do and where do you place the
focus point in order to assure that the face is in sharp
focus? Think of the human head as being divided into
three planes, from front to back. The nose is in the
first plane, the eyes fall in the second plane and the
ears and back of head are in the third plane. If you
chose to place the focal point on the nose, one third of
the distance in front of the nose would be in focus and
two thirds of the distance behind the nose would also be
in focus. That should mean that the entire head would be
in focus. Maybe, maybe not depending on how large an
aperture you are using.
By choosing the nose as the front plane you are
accenting it
and moving the
other planes backwards. Most people would not find this
pleasing. So where else could you place the focal point?
The desired place to focus on a human face is the eyes.
The reason is the same as mentioned above. The human
head is divided into three planes with the eyes being
located in the second third. This means that if you
focus on the eyes, one third in front (the nose), and
two thirds behind (the ears and then hair) will be in
focus. The eyes are the critical points that must remain
sharp.
The focus point is the point at which maximum
sharpness is too be obtained, the degree of sharpness
begins to fade away from this point with the degree of
fall-off depending on the size of the aperture. The
smaller the aperture, the greater the depth of field.
The larger the aperture, the smaller the depth of field.
Here is another example, suppose you are taking photo
of a large group of people and you want the background
to fade away slightly. Because of the light, you are
using a larger aperture. Now how do you insure that
every row will be in sharp focus? Do you focus on the
front row? Or on the back row? Or which row? Go back to
the rule of thirds, remembering that you have about
one-third in front of the focal point and two-thirds
behind. View the group as a block occupying space and
distance. Mentally divide the block into thirds and
place your focus accordingly. Depending on how large an
aperture you are working with, the group should be
relatively in focus and the background should be
slightly blurred.
It is always a tradeoff. What is important and what
isn't. In this situation a professional will start
adjusting light, changing lens, altering distances and
repositioning himself all in an effort to achieve the
precise results he wants. He will choose the best
possible aperture under the conditions. For most amateur
and point and shoot photographers this may not be
possible, so keep the above rule in mind and you can
begin to take great pictures with the available
equipment.
The article
on depth of field goes into greater detail, but for now
we are just covering it as it pertains to composition.
What are we taking a picture of and how do we want it to
look.
Distracting Elements
This is a point that
should be stressed often. Take the time to look around
the viewfinder. The few extra seconds of attention to
details will make a difference in the quality of your
pictures.
