DEPTH OF FIELD

A very interesting part of photography is Depth of Field (DOF for short)

There are set ways to use it but there are certain rules to use it correctly.

  • What effects the amount of DOf we get in an image?

Aperture, distance from the subject to your camera and focal length of the lens

  • How to get a blurred background

A huge aperture f/1.8, f/2.8 even f5.6 depending on the other two

  • how to get everything in focus with landscape photography

a small aperture like f/8 upwards, distance to subject, focal length of lens

  • Do we need expensive equipment?

yes and no. Expensive comes into play when we need big apertures like 2.8 and prime lenses.

In every shot there is a certain area of your image in front of, and behind the subject that will appear in focus.

This area will change from photo to photo. Some pictures may have very small areas of focus which is shallow depth of field. Others images may have a big area of focus which is a big depth of field.

Three factors will affect how you control the depth of field in your images. These are aperture, distance from the subject to your camera and focal length of the lens.

APERTURE:

Very simply t he lower your f-number, the smaller your depth of field. The higher your f-number, the larger your depth of field.

DISTANCE:

The closer your subject is to the camera, the smaller your depth of field is. Moving further away from your subject will deepen your depth of field.

FOCAL LENGTH:

Simply the longer you set your focal length the shallower the depth of field. Example; 28mm at 10 foot away at f/2.8 gives you 7.3 foot DOF BUT if you change the distance to say 100 foot you get infinity. This is because you changed the distance! NOTHING else changed except the distance.

 

So to summarize:

Larger depth of Field

  • Narrow your aperture
  • Further distance from the subject
  • Shorten the focal length (24mm)

Decrease depth of field

  • Widen your aperture
  • Move closer to the subject
  • Lengthen your focal length (200mm)