Lesson 4: Controlling Motion

Kozak02Controlling Motion
by Steve Kozak
M. Photog., CR.
CPP

 

 

 

The shutter speeds not only control the amount of light that reaches the film, but they also control the apparent movement of objects in motion during the exposure.

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Objects that are moving during the exposure will appear almost stationary at fast shutter speeds, and may record as a blur during slower shutter speeds.

fast1Fast Shutter Speed
This image at left was recorded at F2.8 @ 1/250. Notice how the fast shutter speed arrested the movement of her hair blowing in the wind.

slow1

 

 

 

 

 

 

Slow Shutter Speed
This image at right was recorded at F16 @ 1/8 with the camera on a tripod. Notice how the slow shutter speed recorded the movement of her hair blowing in the wind.

By the way, shutter speeds help control movement of the camera by the photographer.

We all have a tendency to shake when we hold the camera. For a picture to be truly sharp, the camera needs to be kept very still during the exposure.

When hand-holding the camera, use shutter speeds that are no slower than the focal length of the lens you are using.

It is recommended that you use shutter speeds with a value that is at least 1/focal length – or faster when your hand-holding the camera.

For example, use 1/250 if you have a 200mm lens on the camera or 1/125 with a 100mm lens. Generally speaking, it is best not to allow the shutter speed to fall below 1/60 when hand-holding any lens.

slow2Slow Shutter Speed
This image at left was recorded with a 100mm lens at F16 @ 1/8 with the camera hand-held.

Notice how the slow shutter speed recorded the movement the camera in my hands.

fast2

 

 

 

 

 

Fast Shutter Speed
This image at right was recorded with a 100mm lens at F4 @ 1/125 with the camera hand-held. Using a shutter speed that is at least equal to the focal length of the lens (100mm = 1/125) allows me to hand-hold the camera and record a sharp image.

Using speeds slower than the focal length of your lens may require a tripod, monopod or some other camera support. Vibration Reduction or Image Stabilization features on a lens will also help keep images sharp at slower speeds.

Welcome to your Lesson 4: Controlling Motion

1. The shutter speeds serve two purposes - what are they?
2. What is the slowest shutter speed that you should use if you are hand-holding your camera?
3. Why would you want to change the shutter speed from 1/60 to 1/250?
4. Which line has the “whole” shutter speeds in the correct order?
5. If you move the shutter speed from 1/125 to 1/250, what happens to the amount of light that reaches the sensor?
6. If you move the shutter speed from 1/60 to 1/30, what happens to the amount of light that reaches the sensor?
7. Which of the following shutter speeds would be best for freezing a moving subject?
8. If you are hand holding the camera with a 200mm lens, which is the slowest speed you should use?
9. How much more light reaches the sensor when you move from F8 to F4?
10. How much less light reaches the sensor when you move from F2.8 to F5.6?