What is Depth of Field - Beginning Photography Basics

At some point all beginning photographers areswitching your mode to Aperture Priority mode -
confronted with certain technical aspects ofor AV mode.
photography that have them either burning upWhile I will not give a detailed explanation about
rolls of film, or loading up memory cards! Two inaperture in this article - the simplest way to
particular: Exposure (which will be addressed in aunderstand is this: An F-stop is the adjustable
different article) and Depth of Field (or DOF) leaveopening that controls how much light coming
the newly shutterbug bitten novice shaking theirthrough your lens hits the film or digital sensor.
head, wondering what they are doing wrong.The shutter speed is involved with this as well,
When I first started taking on an informalbut for now let's stick with aperture. The F-stop
teaching role with beginning photographers it wasalso controls the DOF of an image.
interesting that the single most common questionOlder SLR camera lenses typically have the
asked by them was: "How do I make theF-stop numbers on the lens barrel. An older very
background blurry and my subject sharp?" and ofbasic lens may have numbers around the
course, "what do I need to do when I wantaperture ring like: 2.8 - 5.6 - 8 - 11 - 16 - 22.
everything in focus?"These are the F-stops, or the aperture opening
It's inevitable. If you desire to take yoursettings.
photography to a higher level of quality, you willMore modern cameras are electronic and the
need to understand what causes short and longF-stops are usually seen at the bottom of the
depths of field, and especially how to manipulate itviewfinder. Contemporary lenses usually have
to express your vision. Let's get started...more F-stop settings available, such as: 2.8 - 3.5 -
First - what is a photograph with a short Depth of5.6 - 6.3 - 7.1 - 8 - and so forth, possibly all the
Field, and what is one with a long DOF? Quiteway up to 32.
simply, a photograph with only the subject inTo choose the DOF you wish to use for a
focus, and everything before and behind it blurry,particular shot you need to understand this very
is a photograph with a short DOF. An image withbasic concept: The lower the F-stop number -
everything in the foreground to the backgroundsuch as 2.8, the shorter your DOF will be. The
sharp and in focus has a long DOF. With this highlyhigher the F-stop number - 22, the longer the
sophisticated formula I'm sure you can figure outdepth of field. To simplify it further - making a
what a medium DOF is!photograph with F22 or higher is going to have
Why use a short DOF? When you reach this leveleverything in the final image in focus. Shooting
of being able to control exactly what you want inwith the aperture set at 2.8 is going to mean that
focus (typically referred to as Selective Focus) inonly what you specifically focused on is going to
your photograph you will have developed asharp.
dynamic tool that will create powerfulTake a moment to absorb this because this basic
photographs! You will see this used extensively inconcept is the nuts and bolts of creating a quality
photojournalism - such as the photographerphotograph, rather than just taking a picture. The
focusing on one particular individual in a crowd ofvery best exercise you can do to practice this
people. Creative use of this tool certainly givestechnique is to line up 3 objects - such as apples.
sustenance to the term: A picture paints aPlace them on a table about 2' apart lined up going
thousand words!away from you at just enough of an angle so the
Quite often you will see the use of a short DOFfirst one isn't blocking the other two. Place your
in glamour portraiture. A classic example is whencamera about 3' from the first one, and focus on
you see the model's eye closest to the lensthe apple in the middle. Shoot several shots -
sharply focused, and the one furthest is blurred.each one at a different f-stop, starting with the
It's one of the most unique techniques alowest number (short DOF) and changing to the
photographer can utilize to convey her or hisnext higher f-stop after each shot...all the way to
message.the highest F-stop.
What about a long DOF? Landscape photographyIf your lens has an F-stop number as low as 2.8
is the best example of the long Depth of Field inyou will see that maybe only the forward surface
use. Shooting images of seemingly endless vistasof the apple is in focus - everything from closest
would render a photograph worthless if only ato furthest is gradually very blurry. With each
small portion of the 'field' was in focus. Since youshot changed to a higher F-stop number you will
want virtually everything from closest to farthestsee more of the field in focus. By the time you
tack sharp - you will want to shoot with a longget to the highest F-stop setting, virtually
DOF. You can see this utilized with incredibleeverything in the photo will be sharp and focused.
results in the works of the greatest fine artMost SLR cameras have a DOF Preview Button.
photographers such as Ansel Adams and EdwardIf you use it while looking through the lens at
Weston. But even when making photographs ofyour scene - you will see what the final image will
spectacular scenes, there will be times when yourlook like. Only problem is - the higher the F-stop
creative vision will want to focus attention on anumber is, the smaller the amount of light is let in.
tiny, fragile flower amidst nature's grandestSo it can be very difficult to see because it will be
formations. Developing these techniques will armvery dark. After practicing with these techniques
you with that kind of photographic versatility.you will not bother with the DOF preview button.
So now that you understand what DOF is, howYou will know how the image will be reproduced.
do you make it work? This is where we begin toThat is the mystery of Depth of Field in a nutshell!
get a bit technical, but it's important youYes, there is more in-depth aspects of DOF -
understand it. Since DOF will vary depending onsuch as understanding Hyper Focal Distance, and
the focal length lens you are using, my examplesof course knowing that you will get different DOF
will be in regards to using a normal SLR lens in theresults with longer and shorter focal length lenses.
45mm - 70mm range. To be able to manipulateBut understanding these basic DOF concepts will
DOF you must be able to adjust the aperture (orrevolutionize your photography, and give you one
F-stops) on your camera. Most all SLR camerasmore step up in photographic quality.
that are even remotely modern can do this by