Going shallow or deep: Baseball, digital cameras and depth of field

As the opening of the 2010 baseball season approaches, newspapers, magazines, Web sites and TVs will soon be filled with shots of players swinging, pitching, sliding, leaping, arguing, fighting and, occasionally, getting hit by pitches. In many of these photos, you'll see the effects of depth of field, particularly if they're shot by pros.

Take for example, this photo from last year. As a New York Mets fan, this shot of Mets third baseman, David Wright, getting hit by a pitch still makes me wince. But it's also intriguing for another, more photographic reason.

Because most of the pro photographers use SLRs with lenses that have wide apertures-—that is, f/stops such as f/2.8 or f/2—they can create dramatic images in which just the subject is in focus. As you can see in the David Wright shot, you see no details in the background. The horrified fans are simply amorphous blobs of light and shadow.

On the other hand, David Wright is in sharp focus. You can even see that the tiny beads of sweat from his face are suspended in mid-air (which is also due to the fast shutter speed). So, everything that is near Wright is in razor-sharp focus. If there were anything further in the background or closer to the photographer in the foreground, it would be out of focus.

This is depth of field in action. In the Wright shot, the photo is said to have shallow depth of field. At other times, you may want to have greater depth of field, where most or the entire image is sharply focused.

For more on depth of field, check out these following links:

• Tutorial: Depth of Field 
• Interactive Depth of Field Tutorial
• A Fresh Look at Depth of Field: Using foreground to achieve creative depth of field

You'll can also find out which lenses can achieve shallow depth of field by checking our Ratings of SLR lenses. Look for lenses that have an f-stop that opens up to f/2.8 or wider, such as the Olympus Zuiko Digital 14-54mm f/2.8-3.5 II, $500, instead of the less expensive lenses that only open up to a range of f/3.5-5.6, which won't let you get the same shallow depth of field.

—Terry Sullivan