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TRANSCRIPT
Shutter
• The shutter controls the amount of time that light is allowed to enter the lens and reach the image sensor, or the film.
• Along with the aperture setting and ISO, the shutter speed controls exposure.
• The other function of the shutter speed is to control motion.
Shutter Speeds
• The shutter speed is one of the controls that determine the exact amount of exposure your film or image sensor receives.
• The following is a list of the full shutter speeds, starting with 1 second:
• 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, etc.
• Each of the above shutter speeds is 1/2 the amount of time as the previous speed.
• The shutter speeds listed above are set up similar to f-stops…each speed lets in 1/2 as much light as the previous speed, and twice as much as the next one.
• This allows for different combinations of shutter speed and f-stop to be chosen to get the same exact exposure. So 1/60 at f/8 gives the same exposure as 1/30 at f/11, or 1/125 at f/5.6. The shorter the time (shutter speed) you use, the larger the aperture opening (f-stop) you’ll need to let in the same amount of light.
Shutter Priority Mode
• Using the shutter priority mode on a digital camera lets you set the shutter speed and the camera adjusts the aperture to maintain correct exposure.
• If you want a moving object to be rendered very sharply in your photo, you would need to select a fast shutter speed. And if you want to show the blurring effect you’d select a slow shutter speed.
Controlling Motion
• Camera Movement• Subject Movement• Actual Speed vs. Relative Speed• Distance• Focal length
Camera Movement
• Camera movement happens whenever the camera is moved while the shutter is open.
• One is pressing the shutter release too hard causing the camera to jerk at the exact moment of exposure.
• A shutter speed that is set too low increases the chances of camera movement.
• a shutter speed that is equal to the focal length of the lens reduces the chance of getting camera movement.
• For example, with a 125mm lens, use a shutter speed of 1/125 of a second or faster.
• A tripod and a cable release are also options.
Subject Movement
• If subject is moving fast then use fast shutter speed.• Subject movement can be frozen, so it appears
sharp in the picture, by using a fast shutter speed.• Slower shutter speed would be the On the other
hand, capturing a sense of motion may be more effective than a sharp image, so choosing a better choice.
• Several factors will affect how slow is slow enough.
Actual Speed vs. Relative Speed
• The actual speed of the subject is less important than the relative speed. The direction of the motion in relation to the camera is your primary concern.
• photographing a car going 45 mph. would require a faster shutter speed if it is moving parallel to the camera.
• The same 45 mph. vehicle moving straight towards or straight away from the camera wouldn’t require as fast a shutter speed.
Distance
• The distance between the subject and your camera is another important factor that influences your choice of shutter speed. The closer the moving subject is to the camera, the faster its relative speed will be.
• Therefore, a faster shutter speed is necessary when the subject is very close to the camera and a slower speed will work when the subject is further away.
Focal length
• The focal length of the lens you use will also influence your choice of shutter speed.
• A telephoto, or zooming in on your subject has the same effect as moving closer, and requires a faster shutter speed.
• Using a wide angle lens would be the same as moving further away, and a slower shutter speed could be used.
Putting It All Together
• The first decision you will make is do you want a sharp image or do you prefer to use blur in the image to emphasize the motion.
• Next you should consider the distance factor. Moving closer or farther away might be possible, and using a telephoto or wide angle might be the best option.
• Naturally, because of the variables involved, the only sure way to determine the exact correct shutter speed is to experiment.
To avoid camera movement
• First, it will depend on how steady you are when holding your camera.
• Then using a faster shutter speed whenever possible is a good solution.
• when you are using a longer lens (a telephoto) that not only is the size of the image magnified, but the movement is magnified as well.
• So with longer lenses a faster shutter speed may be needed to avoid camera movement.
• If you must use a slower speed then try to brace yourself and/or your camera or use a tripod or firm surface like a table, a wall or a tree to help steady the camera.
Practice