Photography: Depth of Field

 Depth of Field is the area of clear vision of the camera. Depth of field is defined as the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. So, basically it's that which is in focus.

Depth of Field

Study the PDF below

(to be used for educational purposes only)

Depth of Field/Focus PDF

There are basically two kinds of depths of field.

1.     Deep or broad depth of Field

2.     Shallow or narrow depth of field

We can divide the visual field of a camera into three with reference to distance, namely, foreground, middle ground and background.

When all the three grounds are clearly visible it is called deep/broad depth of field. When only one, or not all the grounds, among the three grounds is clearly visible it is called shallow/narrow depth of field.

Deep Depth of Field

Documentary photographs and news journalistic photographs are mostly taken with deep depth of field. The truth telling capacity of such images are greater. Shallow depth of field, on the other hand, brings simplicity and greater aesthetic appeal to the images.

Shallow Depth of Field

Two factors contribute to creating depth of field,

1.     Focal length of the lens

2.     Aperture

With higher focal length its relatively easier to achieve shallower depth of field. 

Large aperture (smaller aperture number) creates shallow depth of filed.

Focusing 

Lens has to be at a comfortable distance from the subject of shoot for it to begin to see the subject with clarity. This is called Minimum Focus Distance (MFD), or Macro (not to be confused with macro photography).

Camera’s Focus works on two modes.

Auto Mode: The camera focuses on the subject automatically.

Manual Mode: Focus is achieved by manipulating the focus ring on the lens.

There are two other factors that help in focusing 

Autofocus Modes: When on Manual Focus, the photographer controls the focus. Autofocus Modes help in more targeted focusing while on Auto Focus.

Autofocus Points: When on Manual Focus, the photographer controls the focus. So Autofocus points are irrelevant.Autofocus points help in specifying which area on the screen to be focused.