1. Depth Of Field

2. The Depth of Field is a measure of how much ‘depth’ of an image will be in focus.
There are three things which can change the depth of field:
The aperture
The focal length of the lens used
How near the subject focussed on is to the camera

3. Aperture & Depth of Field

4. Camera lens focussed on the barbed-wire Small aperture (f16)
1. Changing the Aperture
Camera lens focussed on the barbed-wire Small aperture (f16)

5. Camera lens focussed on the barbed-wire Large aperture (f2)

6. Small aperture (f22)

7. Large aperture (f2.8) – Note how not all the seaweed is in focus

8. Two photographs from the same position, both with the camera focussed on the wooden beams.
Which image was made using a small aperture and which with a large aperture?

9. Large aperture Small aperture
One of the problems with using a small aperture to get maximum depth of field is that to get the correct exposure a much slower shutter speed is required. This has led to a problem in the right hand image …

10. 1. Where was the camera focussed for both images. 2
1. Where was the camera focussed for both images? Which image was made with a small aperture and which with a large aperture?

11. There are two other variables which also alter the depth of field:
2. Focal length of lens
Long focal length lenses (telephoto lenses) have less depth of field than short focal length lenses (wide angle lenses).

12. F16, 1/250 of a second 24mm (wide angle) lens F16, 1/250 of a second
100mm (telephoto) lens
(To take this picture I had to stand much farther away from the car to get a similar composition)

13. 3. Distance of subject to the camera
The nearer you are to the subject which you focus on, the smaller the depth of field.

14. Three images taken with the same lens and exposure, each focussed on the car.
f5.6, 1/500 second
Camera close to car
f5.6, 1/500 second
Camera further from the car
f5.6, 1/500 second
Camera even further from the car.

15. SUMMARY Depth of field is affected by THREE factors:
The aperture (small apertures give more depth of field)
The focal length of the lens (shorter focal lengths give more depth of field)
The distance from the camera to the subject focussed on (the greater the distance the greater the depth of field).

16. Produce a page in your sketchbook on Depth of Field.
Prep Work
Produce a page in your sketchbook on Depth of Field.
It should include a shoot that experiments with depth of field. Note down shutter speeds and apertures and distances (remember to focus on landscape photography)
And an explanation of depth of field, the 3 factors that affect it, diagrams explaining these and how they are controlled.