NZPhotographer Issue 35, September 2020

IMAGE 5
Use of Depth of Field
Depth of field broadly refers to the parts of an
image that are in focus. I generally prefer a shallow
depth of field – shallow because only a part of the
image is in focus. All but one of the cheese board
images were shot at f2.8 (wide aperture) to create
that shallow depth – an easy technique used to
highlight a ‘hero’ part of the scene.
For overhead shots where it is generally desirable
to have everything in focus, I can still usually get
away with a wide aperture as the required focus
plane is small.
A wide aperture allows more light through the lens so
I can use a faster shutter speed when shooting handheld,
without necessarily having to increase my ISO.
A shallow depth of field really enables you to draw
attention to a smaller area of the image and is
worth experimenting with. Examples of this are
shown on the next page where I've shown the
focus point of each image to highlight the focus
plane.
Notice how your attention is drawn toward the
front of the platter in frame 1 – the cheese stands
out as the hero of the image because it is central
to the image and is the largest object on the focus
plane.
In frame 2, I have kept the aperture wide at f2.8
but shifted the focus plane further back toward the
centre of the platter by focusing on the cheese
knife. Here, the eye is drawn to the knife given its
placement within the image and it being the tallest
object in focus (central to the image).
Objects both in front of and behind that focus
plane remain quite blurred given the wide
aperture. To my eye (this is a personal preference)
this is not as nice an image as frame 1 given there
is too much of the platter blurred in front of the
knife.
We can control the blurriness (and amount of
bokeh) either side of the focus plane by adjusting
our aperture. For example, I can increase the
amount of the image in focus simply by choosing
a narrower aperture. Frame 3 shows this nicely. By
stopping down to f9 I am decreasing the size of the
aperture, allowing less light in but also deepening
the depth of field. The deeper depth of field in
this example, I think, produces a more interesting
image (with more for the eye to easily explore). This
really is a personal preference though and there is
no right or wrong answer when selecting depth of
field unless you are working to a specific customer
brief of course, in which case what they say goes!
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