Depth of Field

Photography Technology I

The Aperture

The aperture is a set of leaf-like pieces of metal that allow the size of a hole in its center to be changed.A change in aperture size changes how much light is let into the camera.

Setting the Aperture

Remember, the aperture setting (f/stop) is inversely proportional to the opening size. (small # = large opening)

The aperture must be set according to the prevailing light conditions.– If the light is dim – “large” aperture openings are required– If the light is bright – “small” aperture openings are required– Why?

Adjusting the Aperture

The aperture dial is usually found between the body of the camera and the lens.On some cameras the aperture f/stop may be digitally displayed on the camera.

Aperture Size Choices

Each setting on the aperture is double the size of the setting before it and one half the size of the setting after it.Aperture dials may also contain an A this setting will automatically adjust your aperture to the correct size based on the current lighting conditions. Some cameras may be set so that one or both settings (Ap. & SS) are automatically adjusted.

Aperture Size Choices

F/stop is a relationship between the opening size and the focal length of the camera.1.4

2

4

5.6

8

11

16

22

32

Controlling Your Background

Other than limiting/ allowing light into the camera, the aperture can also be used to control the look of the background in the photo.Experienced photographers use the aperture to give their photos the effect they desire.This effect on the background is known as a depth of field.

Depth of Field

This is the distance between the closest and farthest objects in focus in your photograph.Depth of field can be used to simplify or emphasize the background of your photos.

Narrow Depth of Field

When a large opening/ aperture is used to increase light, objects in the background/ foreground do not focus well.You can use large openings (small f/stops) to simplify/ blur a complicated or distracting background.

f 2

Deep Depth of Field

When a small opening/ aperture is used to limit light, objects in the background may be focused.You can use small openings (large f/stops) to clarify/ focus a background that is important to the composition of the photo. f 22

Compensating for Aperture Adjustments

Shutter speed & aperture work together to gain proper photo exposure.A fast shutter allows only a small amount of light – aperture must be larger to balance exposure.When aperture is set, the shutter speed must be used to compensate for exposure. (fast for large opening, slow for small opening)

Auto & Semi Auto Cameras

Fully automatic cameras balance both settings to achieve the maximum/ best value for each. Semi-auto cameras allow one setting to be adjusted while the other is automatically calculated. (shutter priority/ aperture priority)Be careful, as the camera may pick an undesirable setting. (ex. Slow shutter) Why might this be bad?

Narrow or Deep DoF

Narrow

Narrow or Deep DoF

Deep

Narrow or Deep DoF

Deep

Narrow or Deep DoF

Narrow

Narrow or Deep DoF

Narrow

Where do we go from here?

You will be expected to capture a variety of nine photographs that illustrate your understanding of how Depth of Field can be changed in a photograph by controlling the aperture.Of these nine photographs, we will be making two 3-1/2 x 5 enlargements.You will be creating two 3-1/2 x 5 enlargements that demonstrate how the aperture can be used to control Depth of Field in a photograph. These enlargements should be made from the best photographs that demonstrate narrow Depth of Field (f/stops of 2, 2.8, & 4) and a deep Depth of Field (f/stops of 11, 16, 22 & 32).

Review

What is the aperture used for?When are large apertures used?When are small apertures used?How will you determine the correct

shutter speed?Any Questions?

Change the amount of light let into the camera

Dim lighting conditions or when creating a shallow/narrow depth of field effect

Bright lighting conditions or when creating a large/deep depth of field effect

Balance your light meter using the cameras shutter controls