Aperture and Depth of Field

Review• What are the three controls on the camera that control

proper exposure?

Shutter speed• This controls how much light

your picture gets by how much TIME your exposure is.

• The TIME is controlled by how long the camera’s shutter (or window) is open

• If the shutter is open for a long time, it gets more light

• If it’s open for a short time, it gets less light

ISO• This controls how much light your picture gets by how

sensitive the digital sensor (or film) is to the light. This also controls how much “noise” your photo has. The higher the number, the more light the sensor will get, but the image will be more noisy/poorer quality. Rule: shoot at the lowest ISO you can.

APERTURE (F/STOP) learning targets 1. What is it?2. Where is it?3. What does it do?4. When do you use it?5. Why would you use F/2.8?6. Why would you use F/22?

THIS IS APERTURE, Also called an F/stop

Aperture- this is the size of the opening in the lens

It controls:

- how much light is let in through the lens- Depth of field

Every aperture setting is called an f/stop, or a whole stop of light

To increase the aperture is to open up. Every stop you open up, it lets in twice (or 2x) as much light. (example: if you are at f/8 and open the aperture to f/5.6 you are letting in twice as much light.

To decrease the aperture is to stop down. Every stop you stop down, you let in half as much light. (example: if you are at f/8 and stop down to f/11 you are decreasing the light by half.The standard f-stops you need to memorize are: f/2,f/2.8,f/4,f/5.6,f/8,f/11,f/16,f/22,f/32

If you open up your lens, you must increase your shutter speed. If you stop down, you must decrease your shutter speed.

What settings let in the most/least amount of light.

Aperture also controls the Depth of Field

What is Depth of Field?• A camera can only focus its

lens at a single point, but there will be an area that stretches in front of and behind this focus point that still appears sharp.

• This zone is known as the depth of field. It’s not a fixed distance, it changes in size and can be described as either ‘shallow’ (where only a narrow zone appears sharp) or large/greater/complete (where more of the picture appears sharp).

Shallow vs. Greater (or complete) Depth of Field?

f/1.8 Shallow depth of field

f/16 Greater depth of field

Shallow (or narrow) Depth of field• The shorter the focal distance you

are from the subject, the shallower the depth of field. You have to be within about 10-15 feet of your subject to get a shallow depth of field

• Good for emphasizing your subject. Or blurring out distracting backgrounds.

• Shallow depth of field is usually f/5.6 and below. The lower the number, or the more wide open the aperture, the more extreme the blur.

• Shallow depth of field lets in a lot of light, the aperture is wide open. So this will affect how fast the shutter speed is. HOW?

What causes the blurring?• when an object is in focus, light rays originating from that point

converge at a point on the camera's sensor. If the light rays hit the sensor at slightly different locations (arriving at a disc instead of a point), then this object will be rendered as out of focus — and increasingly so depending on how far apart the light rays are.

Examples of a LARGE Aperture- shallow depth of field

Focal distance also affects depth of field. • If your subject is far

away from the camera, the greater (or more complete) the depth of field. You would not be able to get a shallow depth of field no matter what aperture you use.• Mostly used for

landscapes or for subjects you don’t want to have blurring.

Greater or complete depth of field• More parts of the picture are in focus• If everything is in focus it’s considered a complete depth of

field• Complete depth of field is usually higher # f/stops, like f/16 or

f/22• Question: How much light would these f/stops let in?• Answer: not much, it’s a small aperture!• So what happens to the shutter speed then?• Remember, DO NOTlet the shutter speed go under 60!!

What if the shutter speed makes me go under 1/60?• What can you do?• You can use a tripod.• Or bump up the ISO higher, this will allow more light to hit the

sensor, and you can shoot above 1/60 shutter speed. BUT this will result in a poorer quality photo.

ISO

Examples of a SMALL Aperture- complete depth of field(f/22)Good for landscapes and for subjects you want entirely in focus.

You can be close up to a subject and still get a complete depth of field by using f/16 or f/22.

Now it’s your turn…

Shallow Depth of Field or Complete Depth of Field?

Can you have a shallow depth of field with this subject?Why or why not?