Depth of Field
Depth of field is the difference between the distance of the nearest and farthest object appearing in the final image, which appears sharp to the human eye.
Shallow depth of field
Shallow depth of field (shallow focus) is achieved by highlighting the subject and its separation from the background. It is used for example when shooting portraits.

Source: Wikipedia.org
Large depth of field
Large depth of field (deep focus) is achieved by focusing on near and distant objects in the image. It is used for example when photographing landscapes.
Source: Wikipedia.org
Effects of the depth of field
- The greater the focal length of the lens (more zoom), the depth of field is smaller.
- The closer the subject is, the smaller the depth of field is.
- The lower the f-number (eg. f-2.8), the depth of field is smaller.

