A shallow depth of field can be used in portraits to focus attention on the eyes (as in the portrait on the left), whilst a greater depth of field is useful for landscapes to ensure acceptable focus throughout the scene.

In the example, a 'Shallower Depth of Field' would mean the second girl would be 'Softer', while a 'Greater Depth of Field' would mean she would be 'Sharper'.

Controlling Depth of Field

Depth of field is controlled / affected by the length of the lens used, the aperture used, and the size of the Cameras CCD.

The longer the lens, the shorter the Depth of Field. The wider the lens, the deeper the Depth of Field.

The larger the Aperture (ie: f2.8), the shallower the Depth of Field, the smaller the Aperture, (ie: f11), the greater the Depth of Field.