Photography For Beginners: Depth of Field.

Photography For Beginners: Depth of Field.
Depth of field is one of the most important aspects of
photography you can learn. Use depth of field well in your
photography and you can gain immense control over the look
and impact of your photos. Unfortunately, depth of field
also seems to be one of the toughest aspects for beginners
to learn and master.

Even when you break it down to the simplest terms, the
relationship between aperture and depth of field can seem
confusing. Whenever I teach a class, or try to explain the
manual settings on a friend's camera, this is the always
topic we have to go over again and again. The good news is
that with practice and concentration, the aperture/depth of
field relationship will finally 'click' for you. The bad
news is, there is more to understanding depth of field than
just using your aperture.

But let's start at the beginning. What is depth of field?

In simple terms, the depth of field is the area behind and
in front of your main point of focus, that is also
acceptably in focus. So if you focus on a subject one metre
away, you might look at your photo and find that everything
from 0.9 to 1.2 metres is in focus. In this case, your
depth of field is 0.3 metres (30 centimetres).

The very first thing a new photographer learns about depth
of field is that it is controlled by the aperture on your
lens. Very simply, a smaller aperture creates a larger
depth of field, and a larger aperture creates a narrower
depth of field. So if we go back to our previous example,
let's say the 30cm depth of field was captured with an
aperture of F-8. You could narrow the depth of field
considerably by adjusting the aperture to F-2.8, a much
wider setting.

Sound confusing? It is hard to explain it any more simply,
especially without showing you photos as examples. If this
is your first time working with depth of field, don't
worry. Go outside right now and take some shots just as I
have described, and you should be able to see the results
right away.

So if it is that simple, why do so many people struggle
with depth of field? As I wrote earlier, there is more to
depth of field than just the aperture.

Depth of field is also affected by how close the subject
appears in your photo. That means either how close you are
to the subject, or how much you magnify or reduce the
subject using different sized lenses.

The closer you are to your subject, or the closer you make
the subject appear by zooming in with your lens, the
smaller the depth of field becomes. Let's say you are
photographing a person five metres away. At this distance,
a standard or wide-angle lens will not only show a lot of
background, but the wide depth of field could make the
background quite distracting. However, if you walk much
closer to the subject and re-focus, the depth of field will
become much smaller. As a result, the well-focused person
will stand out clearly from a blurry background. You can
maximize the effect by opening the aperture to its widest
setting.

Now imagine your subject is posing in front of a beautiful
waterfall. If you stand close to the subject and photograph
them with a wide aperture, you could get a great shot of
the person but the waterfall will be an out of focus blur.
You could improve the situation slightly by closing the
aperture a few stops. However, the most effective way to
improve the depth of field is to stand a few metres further
back, and/or zoom back to a wider angle with your lens. Not
only will you capture more of the background, but it will
be much sharper than if you only adjusted your aperture
alone.

So there you have a quick look at not one, but three
factors than can make it easier to master depth of field;
aperture, distance from the subject, and the size of the
lens. This really is a topic that needs to be illustrated
with a few photos, but hey - you have a digital camera. Why
not go and try out these ideas at the next opportunity? It
won't cost you anything, and you can see the results right
away. You will soon develop a feel for the best way to make
depth of field work for different subjects in your
photography.

----------------------------------------------------
Depth of field is better explained and illustrated in
Andrew Goodall's ebook "Photography In Plain English" found
at http://www.naturesimage.com.au/page/25/default.asp .
You will also find plenty of other great resources for
photographers, including a guide to making money from your
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