Depth of field definition

Depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image (source: wikipedia.org).

It mean The images that we shoot had a lot sharpness in every inch of the picture, or we can see all side of the picture had a full focus in every images area.

Depth of field appears in focus from foreground to background and is determined by a combination of the opening of the aperture and the focal length of the lens. A small aperture setting results in greater depth of field.

To taking landscape photograph which all need everything to shows up, its need a large Depth of Field (DoF), so people can adjust the smallest possible of aperture settings.

In general, Depth Of Field is influenced by three things such as:

1. Focal length of the lens used

The width of the sharp inverse of the square of the focal length. In other words, the width of the space will be 4x sharper if we change the original width from 100mm to 50mm lens (the lens focal length and a half from the beginning).

The more wide-angle of lens, the more extensive regions of sharp space of your image result. This means that, when the camera is going to zoom out, the object that we will shoot more freely to move forward or backward within a certain distance from the camera and still look sharp / focus.

2. Aperture

Width sharp space is directly proportional to the diaphragm. Example: if the diaphragm is raised 2 stop of f / 8 to f/16, then the width of the sharper will be 2x the width of the original.

3.The main focus range of the camera

Width sharp space is directly proportional to the square within of objects. If we change the distance between the camera and object of 3x (further - by moving the camera back from its original position), the width of the sharper will be 9x from the original.

Controlling depth of field is one of the easiest ways for a photographer to compose the image. By limiting the depth of field of an image, the photographer can turn the attention of the viewer on the subject in focus.

Often, limiting the depth of field of an image helps eliminate clutter in the background. On the other hand, when shooting a landscape, you want the image to have great depth of field. Limiting the depth of field to the foreground would not make sense.