Photography One Traci Reitz, CCA

What is depth of field? Depth of Field is the amount of a photograph which is in acceptably sharp focus from the foreground to the background

Why is it useful to understand depth of field? It allows a photographer to control the amount of the photograph which is in sharp focus to enhance the effectiveness of the image

Everything in focus

Main subject in focus – background blurred but recognisable

Main subject in focus – background totally blurred

What influences depth of field? The focal length of your lens:  wide angle lens = more depth of field  telephoto = less depth of field The distance from the subject:  further away = more depth of field  closer = less depth of field The aperture of your lens

Aperture Aperture is the opening in your lens which lets in light reflecting from your subject Aperture is measured in f stops. Typically lenses will have apertures from f2 to f36 Just to confuse, large apertures have small numbers and small apertures have big numbers!

Aperture Each aperture allows in half or double the amount of light as you move up or down the f stops Your camera may also be able to move up and down the scale in smaller steps with 2 or 3 positions between the ‘official’ f stops Aperture has a significant impact on depth of field:  A large aperture will give a small depth of field  A small aperture will give a greater depth of field

Why does aperture affect depth of field? The explanation is a little bit technical: The non-technical explanation is simpler - it just DOES! That works for me!

F 5.6 1/3200 small depth of field F 5.6 1/3200 small depth of field

F 11 1/1000 medium depth of field F 11 1/1000 medium depth of field

F 36 1/80 large depth of field F 36 1/80 large depth of field

How do you work out what the DoF will be? There are 5 possibilities:  Ignore it – don’t worry…. be happy!  Use the depth of field preview if your camera has one. This provides you with a visual check  Use the depth of field scale if your camera has one

How do you work out what the DoF will be? There are 5 possibilities:  Ignore it – don’t worry…. be happy!  Use the depth of field preview if your camera has one. This provides you with a visual check  Use the depth of field scale if your camera has one  Use a depth of field calculator

Get this online

How do you work out what the DoF will be? There are 5 possibilities:  Ignore it – don’t worry…. be happy!  Use the depth of field preview if your camera has one. This provides you with a visual check  Use the depth of field scale if your camera has one  Use a depth of field calculator  Make an educated guess!

Hyperfocal Distance and Focussing The hyperfocal distance is the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp. When the lens is focused at this distance, all objects at distances from half of the hyperfocal distance to infinity will be acceptably sharp.

Hyperfocal Distance and Focussing There are three ways to set your focus to the hyperfocal distance:  Use the scale on your lens – if you have one!

Hyperfocal Distance and Focussing There are three ways to set your focus to the hyperfocal distance:  Use the scale on your lens – if you have one!  Use a chart Get this online

Hyperfocal Distance and Focussing There are three ways to set your focus to the hyperfocal distance:  Use the scale on your lens – if you have one!  Use a chart  Guess!

Using depth of field Set your camera mode to AV - Aperture Value Choose your subject and compose your shot Set your chosen aperture If you have a depth of field preview, use that to check the DoF Check your shutter speed If it’s fast enough – take the picture If it’s too slow:  Use a tripod ……. OR  Increase the ISO until the shutter speed is acceptable

Shutter Speed Shutter speed determines the amount of time the lens remains open when you press the button Similar to aperture, shutter speeds double or halve the amount of time the lens is open as you click through the different speeds A photograph’s exposure is set by a combination of shutter speed and aperture Shutter speed has no impact on depth of field

Finding out more Google ‘depth of field’Google Dofmaster website

Questions?