Warning! Technical Term Ahead!

Depth of Field

Straight from Wikipedia: "In optics, particularly as it relates to film and photography, depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image."

When I was first learning photography, this was where my eyes glazed over and my brain shorted out.

Lets go back to last week and compare the little mountain and the little portrait on the wheel.

The mountain, or "Landscape" mode makes the aperture as small as possible, and adjusts the length of time that the lens is open so that the sensor or film receives the proper amount of light. The effect is to keep the foreground and background all in crisp focus.

Monroe Payne: "Cornell Rain"

In this case, you have a "Great" or "Large" or "Long" depth of field, or a large area that is acceptably in focus.

Now to the little portrait icon, or "Portrait" mode. In this case, the camera opens the lens as wide as possible to get the plane of the face in focus, but blurs out everything else, in front of and behind the face. Of course, this doesn't HAVE to be used on a face. It's just a good example.

Kim McAlear: "Dew"

This gives you a "Short" or "Small" depth of field.

So how can you use this?

It is our job as photographers to capture images that tell the story, but ONLY the story. A photo of a statue might be nice, but if the photo also captures, in sharp detail, the messy garbage can across the lawn, it takes away from the impact of your image.

We need to eliminate distractions, but I'll cover that in greater detail next week. Controlling your depth of field is one of many strategies we can use to eliminate those distractions.

Conversely, if we have a spectacular, sweeping landscape with some beautiful flowers in the foreground, the image really loses credibility if the flowers are blurry.

Chelsea Gordon: "Guitar Strings"

So where can we use depth of field as an end in itself, as an artistic tool?

Check out Chelsea Gordon's exquisite study of Guitar Strings, or Kim McAlear's Flower with Dew for examples of extremely short DOF. Large aperture, shorter exposure. f1.8

Jennifer Path: "Across the Fence"

Then look at these great depth of field images by myself and Jennifer Path. Small aperture, longer exposure. f22

Modern cameras have aperture priority settings. Lets go back to our little wheel. Aperture Priority means that the camera will accept your aperture setting manually, then magically adjust the shutter speed to compensate. The setting is usually identified as "A"-something. Canon cameras show "Av" on the wheel... The example last week just has "A".

Monroe Payne: "Theater Entrance"

Homework for this week - play with the aperture priority setting on your camera. Use the guitar strings and the barbed wire fence as templates. Then, intentionally set the aperture the other way. See which way is better. Have a little fun with it.

IthacaStock.com images by Kim McAlear, Chelsea Gordon, Monroe Payne and Jennifer Path. Please visit their galleries at IthacaStock.com.

IthacaStockTips is a free service from IthacaStock.com, and is intended to be used by individuals to increase their proficiency in photography. The information here may be copied and used, provided credit is given to Monroe Payne and IthacaStock.com LLC.