Photography One Traci Reitz, CCA
Photography One
Traci Reitz, CCA
What is depth of field?
• Depth of Field is the amount of a photographwhich is in acceptably sharp focus from theforeground to the background
Why is it useful to understand depth of field?
• It allows a photographer to control the amountof the photograph which is in sharp focus toenhance the effectiveness of the image
Everything in focusEverything in focus
Main subject in focus – background blurred but
recognisable
Main subject in focus – background blurred but
recognisable
Main subject in focus – background totally
blurred
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 lightreflecting from your subject
• Aperture is measured in f stops. Typically lenseswill have apertures from f2 to f36
• Just to confuse, large apertures have small numbersand 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 5.61/3200
small depth of field
F 5.61/3200
small depth of field
F 111/1000
medium depth of field
F 111/1000
medium depth of field
F 361/80
large depth of field
F 361/80
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 onlineGet 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 onlineGet 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 halvethe amount of time the lens is open as you clickthrough 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’• Dofmaster website
Questions?