Depth of Field and Focus

Depth of Field is the area a certain distance from your digital camera that will be in focus. The area can be narrow or deep, depending on your settings, including the aperture, or size of the camera opening that lets light in. What this means is that using certain settings will give you a blurry background while other settings will bring the background into sharp focus.

Portrait Mode
In flower photography, a blurry background is often desirable so the focus of the picture will be on the flower itself. In this case, the flower picture can be comparable to a portrait. The Portrait Mode of your camera is usually identified by a woman's head, often with a hat on. Using this mode in flower photography will give you a pleasing soft focus background.

Macro Mode
Your Macro, or closeup mode, is identified on your camera with a small tulip. Macro mode is for three feet or closer, and with a narrow depth of field, which will give you blurry backgrounds. Too close, however, and your camera may have a hard time coming into focus.

The picture of a curly willow above was taken using Macro mode. Since the willow leaves are green against a green background, the Macro mode allows the narrow leaves and stem to be visibly in focus. You can see how narrow the depth of field is since some of the willow leaves closer to the camera (the lower left area of the photo) are, in fact, also out of focus.

Large Aperture, Narrower Depth of Field
If you are brave enough to experiment with your Aperture, you will discover that the larger the aperture, the narrower the depth of field--and the blurrier the background. The Aperture, or f-stop, is a function of the lens. The smaller the number, the larger the aperture, and the narrower the depth of field.

On many digital cameras the lowest f-stop is f/2.8, which will give you a very narrow depth of field and nice blurry backgrounds. The higher the f-stop, the greater the DOF.

Landscape Mode
Of course there will often be times when you want everything in focus. In fact, you may want to try the Landscape mode, which will pull a background toward you.

These may not be flower pictures below, since they are, in fact, engagement photos. But you can see the difference in the backgrounds. One picture was taken with an automatic setting, the other with a Landscape setting. Can you see where the in the second picture, the grain bin and Vale Butte seem much closer?

For more information on Depth of Field, try the following websites:

Depth of Field for Digital Cameras - A Brief Primer
Digital Photography School Aperture
Depth of Field Tutorial by Cambridge Colour

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