Focus and Depth of Field | Digital Camera Know-Hows | Digital Camera | Digital AV | Support

Digital AV Support > Digital Camera > Digital Camera Know-Hows > Focus and Depth of Field

Text begins from here.

Bringing an image's subject into focus is one of the primary goals of photography. Additionally, considering the areas immediately in front of and behind the focus point (depth of field) help to create professional-looking photographs. When the area in focus in front of and behind the focus point is small, the depth of field is said to be "shallow." When this area is large, the depth of field is said to be "deep." The amount of depth of field can be adjusted by changing the aperture of the lens.

result of using different depths of field

As the aperture of the lens is opened (becomes larger), the depth of field becomes shallower, and as the aperture is closed (becomes smaller), the depth of field becomes deeper.

In addition to changing the aperture of the lens, depth of field can be controlled by the following elements:

The lens' focal length
Distance from the subject

When using a wide-angle lens with a short focal length, the depth of field is deep, and when using a telephoto lens with a long focal length, the depth of field is shallow. Also, when the camera is far from the subject, the depth of field is deep. As the distance between the camera and subject becomes shorter, the depth of field becomes shallower.