When I approach writing these articles, I always do a bit of research just so that I’m sure of what I’m bringing to you, and to organize my thoughts.  I have to say that if I did not already have a working knowledge of depth of field, I would have run screaming into the night!  Being self taught, I understand visually what I’m talking about, but may not always know the science or math involved in the process.  Yes, there is a lot of technical know-how necessary to completely understand depth of field, but I feel that goes beyond what I’m trying to accomplish here. 

So get to it already…what is depth of field?

Depth of field refers to the range of acceptable sharpness  in a photograph from near to far.  What that means is that each photograph has a focal point.  Depth of field is how much of the foreground and background are in focus.  Focus tapers off gradually.  In the photograph below, the red apple on top is the focal point.  Notice how the focus drops off coming toward the foreground, and moving toward the background.

Shallow depth of field

Shallow depth of field is just what it sounds like.  It is when very little in front of, or behind the focal point is in focus.  Below is a photograph that depicts that.  Notice how one orange is in focus, but the focus drops off sharply.

Wide depth of field

On the other end of the spectrum, there is wide depth of field.  this is where much in front of and behind the focal point of the picture is in focus.  Below is a photograph that has a wide depth of field.  Even the person walking in the background, beyond the surfboards is in focus.

Factors that affect depth of field

The first factor that affects depth of field is the aperture, or “f-stop”.  When you take a photograph, the aperture, or opening, snaps open and shut quickly to expose your film, or sensor (in digital photography) to light.  Some point and shoots will not show an f-stop range, but SLRs and some point and shoots will.  The f-stop range should be on the lens itself.  The lower the number, the more light that the lens can gather, and higher numbers, less.  The lower the f-stop, the more shallow the depth of field will be.  The apples and oranges above were shot at an f-stop of 1.8, the surfboards were shot at f-16.

 The other way to control your depth of field is by controlling how close you are to your subject.  The closer you are to your subject, the more shallow your depth of field.  The picture of the plant below was taken farther away.  Notice how nearly everything in the shot is in focus.

In the next photograph, I moved in much closer to capture the flower.  Notice in this shot how nothing except for the flower is in focus.

Which is better?

When it comes to depth of field, there is no right or wrong.  It often depends upon the preference of the photographer or the situation.  If you’re shooting a landscape, generally a wide depth of field is called for.  Are you trying to capture the lattice of a dragonfly’s wing?  Then you’re probably going to want a shallow depth of field.  If you camera has the capability to manually override your f-stop, do it, and play with it.  Try different exposures and distances, and find out what appeals to you!