Controlling Your Controlling Your CameraCamera’’s Shutter Speeds Shutter SpeedDigital PhotographyDigital Photography

3 factors control how 3 factors control how your camera takes a your camera takes a photograph: photograph:

Shutter SpeedShutter Speed

ApertureAperture

Focal-Length of LensFocal-Length of Lens

A slow shutter speed keeps the shutter A slow shutter speed keeps the shutter open longer and shows motion blur.open longer and shows motion blur.

A fast shutter speed captures the motion without A fast shutter speed captures the motion without blurring because the shutter is open only briefly.blurring because the shutter is open only briefly.

A large aperture opening produces A large aperture opening produces photographs with a shallow depth of field. photographs with a shallow depth of field. Less of the photo is in focus.Less of the photo is in focus.

A smaller aperture produces a greater A smaller aperture produces a greater depth of field making more of the scene depth of field making more of the scene in focus.in focus.

A short focal length lens captures more of A short focal length lens captures more of the scene. It does not allow you to zoom the scene. It does not allow you to zoom in on your subject.in on your subject.

A long focal length lens allows you to get A long focal length lens allows you to get in closer to your subject.in closer to your subject.

Your viewfinder or LCD monitor shows Your viewfinder or LCD monitor shows both the shutter speed and the aperture both the shutter speed and the aperture used.used.

Your viewfinder or LCD monitor shows Your viewfinder or LCD monitor shows both the shutter speed and the aperture both the shutter speed and the aperture used.used.

Here the viewfinder shows that the Here the viewfinder shows that the shutter speed is 1/250shutter speed is 1/250thth of a second and of a second and the aperture is f16.the aperture is f16.

Two controls adjust the amount of Two controls adjust the amount of lightlight that reaches the sensor: that reaches the sensor:1. the shutter1. the shutter

Two controls adjust the amount of Two controls adjust the amount of lightlight that reaches the sensor: that reaches the sensor:1. the shutter1. the shutter2. and the aperture2. and the aperture

The combination of The combination of the shutter speed and the shutter speed and the aperture is called the aperture is called the EXPOSURE.the EXPOSURE.

ShutterShutter

Adjusting the length of Adjusting the length of time the time the shuttershutter remains open controls remains open controls the amount of light that the amount of light that reaches the light-reaches the light-sensitive surface.sensitive surface.

There are two main There are two main types of shutters: Leaf types of shutters: Leaf shutters...shutters...

Leaf shutters are usually located within the lens itself.

The “leaves” open and close to let in light.

...and Focal-plane ...and Focal-plane shutters.shutters.

Focal-plane shutters are built into the camera body. The curtains

move across the sensor exposing it to light in equal amounts.

Image in viewfinderImage in viewfinder

Image in viewfinderImage in viewfinder

Image in viewfinderImage in viewfinder

Image in viewfinderImage in viewfinder

Image in viewfinderImage in viewfinder

Image in viewfinderImage in viewfinder

The amount of time the The amount of time the shutter is open is shutter is open is measured in measured in stopstops.s.

Doubling the amount of Doubling the amount of time the shutter is open time the shutter is open gives gives one stopone stop more more exposure or exposure or twicetwice the the amount of light.amount of light.

Halving the amount of Halving the amount of time the shutter is open time the shutter is open gives gives one stopone stop less less exposure orexposure orhalfhalf the amount of the amount of light.light.

Older, analog (non-Older, analog (non-digital) cameras usually digital) cameras usually can only adjust shutter can only adjust shutter speeds in increments of speeds in increments of full stops.full stops.

This chart shows actual times the shutter is open and the designations shown on the camera.

Here you can see that the stops are double or half the stop above or below them.

These are the actual numbers that the analog camera displays for each of these full stops.

With analog With analog cameras, shutter cameras, shutter speeds are adjusted speeds are adjusted manually with the manually with the speed dial on top of speed dial on top of the camera.the camera.

Newer analog Newer analog cameras and cameras and most digital most digital

cameras can cameras can make many make many

more shutter more shutter speed speed

adjustments adjustments than the older than the older

cameras.cameras.

DonDon’’t t confuse 2 confuse 2 meaning meaning 1/2 second 1/2 second with -2 with -2 meaning 2 meaning 2 seconds!seconds!

On a digital On a digital camera, you camera, you can see your can see your shutter shutter speed in the speed in the viewfinder.viewfinder.

On a digital On a digital camera, you camera, you can see your can see your shutter shutter speed in the speed in the viewfinder...viewfinder...

You can also see You can also see your shutter your shutter speed in the data speed in the data panel readout.panel readout.

The faster the shutter speed,The faster the shutter speed,the sharper a moving subject will be.the sharper a moving subject will be.

1/30 second1/30 second 1/500 second1/500 second

The direction of a moving object affectsThe direction of a moving object affectsthe amount of blur.the amount of blur.

When an object is moving directly toward or away from When an object is moving directly toward or away from the camera, no sideways movement is recorded so a the camera, no sideways movement is recorded so a

minimum of blur is produced, even at a relatively slow minimum of blur is produced, even at a relatively slow shutter speed.shutter speed.

1/30 second1/30 second

Panning keeps a moving subject sharpPanning keeps a moving subject sharpwhile blurring the backgroundwhile blurring the background

During panning, the camera is movedDuring panning, the camera is movedin the same direction as the subject.in the same direction as the subject.

The result is a sharp subjectThe result is a sharp subjectand a blurred background.and a blurred background.

1/30 second1/30 secondcamera pannedcamera panned

When planning to pan,decide where you want the subject to be at the moment of exposure, start moving the camera a few moments before the object reaches that point, and continue that motion after the exposure (follow through) as you would

with a golf or tennis stroke.

Generally, the amount of motion blur will double if you increase the shutter speed by one stop (toward a longer

time).Say change shutter speed from 1/60 to 1/30 of a second.

Here are some general shutter speed guidelines for taking photos with action parallel to the image plane.

Notice that the closer you are to the subject, the faster your shutter speed must be.

Motion slows at the peak of an action that Motion slows at the peak of an action that reverses.reverses.

Here the boy jumps from an overturned garbage can for a slam dunk. Here the boy jumps from an overturned garbage can for a slam dunk. Because the photo was taken at the peak of the action where it slows Because the photo was taken at the peak of the action where it slows

down, the shutter speed does not have to be as fast.down, the shutter speed does not have to be as fast.

Clifford Oto, Clifford Oto, Slam DunkSlam Dunk, 1990, 1990

Here the camera moves against a Here the camera moves against a stationary subject.stationary subject.

Laszlo Moholy-Nagy, Untitled, c. 1941Laszlo Moholy-Nagy, Untitled, c. 1941

• Camera and subject are both in motion.Camera and subject are both in motion.

Simon Bruty, Simon Bruty, World Swimming Championships, SpainWorld Swimming Championships, Spain, 2003, 2003

Camera is held still while part of the Camera is held still while part of the subject moves.subject moves.

Oliver Follmi, Oliver Follmi, Pilgrimage to Bodghaya, India,Pilgrimage to Bodghaya, India, 20022002