Digital Slr Photography 101

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How to Use Depth of Field Effectively

Understanding and manipulating depth of field in an image is a key skill of professional photographers. A firm grasp on this concept can improve the quality of your work and can provide you with countless alternative ways to shoot one subject. Depth of field can seem complex and confusing, but with a little bit of practice controlling it will be almost second nature.

The Definition of Depth of Field

In a photograph, depth of field can be thought of as how "deep" the focus of an image goes. In more simple terms, the depth of field refers to the difference between the items in the background losing clarity compared to the subject in focus. Think of depth of field as the relationship between the focused and blurry elements of your photograph.

For instance, a photograph of a flower with the entire background showing as blurry would have a low depth of field, while a photograph of a long subway platform with both near and far subjects in relatively clear focus would have a high depth of field.  In these examples, altering the depth of field would create a different experience to what the viewer sees when looking at each image.

What Influences Depth of Field?

The main factor influencing depth of field in any picture is the time of its exposure. The longer a frame of film or digital sensor has to absorb the scene it is being exposed to, the greater amount of detail it will be able to accurately reproduce. Longer exposures will always result in greater depth of field, even if at unperceivable levels.

When it comes to changing depth of field, you can control it by increasing or decreasing the exposure time. You can do this by changing the shutter speed of your camera; slow speeds (60 and lower) will cause longer exposures and greater depth, while fast speeds (125 and higher) will decrease exposure times and cause the opposite.

Tips for Working with Depth of Field

Although you can intentionally make your images have greater depth of field, this will require you to adjust the aperture settings of your camera manually. Because a longer shutter speed is required to add depth of field, less light must be allowed to enter through the lens. If you up your exposure but you don't close the aperture on your camera your photographs will be end up over-exposed.

Adjusting the aperture requires only moving the f-stop (usually a ring around the lens behind the focus ring) to whichever value will allow for the ideal amount of light. Most modern cameras will allow you to choose a shutter speed and will automatically adjust the f-stop accordingly, but if you have an older SLR you'll need to play with the light meter until the shutter speed you want syncs up with the correct aperture setting.

Tip:  If you're planning on working with high depth of field, the chances are good that depending on your light source you will be working with impossibly long exposure times. Shots of this nature will almost always require a tripod to prevent blurring from camera-shake.

Depth of field is a powerful tool in the photographer's toolbox and should be considered in every photograph you take. Objects in a photograph all lend themselves to the story that image is trying to tell - what is and isn't in focus can mean quite a lot to the relationships between those objects. Think carefully about what you can say about your subjects with depth of field before shooting and your photos will be more powerful and more interesting as a result.

About the Author

Autumn Lockwood is a writer for Your Picture Frames. Shop online and see our selection of friends and family picture frames in a variety of styles, sizes and colors. Visit our website and see our stylish family picture frames and fun friends picture frames or call us at 800-780-0699.

Aperture Shutter Speed and ISO, Photography 101


digital slr photography 1015
digital slr photography 1015