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سرعة الغالق والضبابية .. تقنية الكاميرا .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
Shutter speed and blur
A camera with a range of shutter speeds helps you to give correct exposure under all kinds of lighting conditions and , just as important , it allows you to choose whether movement will record " frozen " or blurred . A stationary subject photographed with the camera supported on a tripod will appear the same at any shutter speed . But if your subject is moving ( or if you are holding the camera unsteadily ) , different shutter speeds will produce quite different results .
As we have seen the shutter speed deter- mines the length of time that the film is exposed to the image . So the slower the shutter speed , the greater the blur created by subject movement . The exact effect depends on how fast the subject is moving in relation to you , how near you are to the subject , and whether the movement is side - on or directly toward the camera . A fast shutter speed is most likely to record all movement as if stationary .
Some photographers use the fastest shut- ter speeds to avoid recording accidental camera movement , but this can destroy any sense of action . With slower shutter speeds you can achieve many kinds of atmospheric effects , through diffusion and blur .
Supporting the camera :
Different shutter speeds not only freeze or blur subject movement but also suppress or exaggerate any movement of the camera during exposure . For most photo- graphs you need to keep the camera absolutely still ( this way stationary subjects appear without blur ) . Shutter speeds of 1/250 sec or faster rarely show camera shake , provided you are standing still . 1/125 sec is also safe , but remember to depress the shutter release gently - don't just jab it . For slower speeds you really need to provide extra support for your camera . Press your elbows into your waist , use your knee or , bet- ter still , the ground or a table as a base . Sometimes you can press the camera hard against a wall , or something similar , which will give sufficient support for longer ex- posure of 1 sec or so . But for the best results use an adjustable tri- pod , below , and a screw - in cable release for the shutter . Provided the ground is firm you can then safely make long exposures .
Shutter speed and subject movement :
The cyclists were moving at the same speed in each of these three pictures , but the exposures were 1/30 sec . right , 1/125 sec . below left , and 1/500 sec . below right . You can see how the fastest shut- ter setting freezes the action - the image remains on the film so brief- ly that no movement has time to record . The slowest , at 1/30 sec . has blurred the group of cyclists , separating them from their back- ground and creating a strong im- pression of speed . At 1/125 sec there is more detail and only the fastest moving elements - the outer spokes of the wheels show blur although the sense of action is still present .
Blur and direction of movement :
Unlike the pictures of the cyclists opposite , all three pictures here were taken with the same shutter setting 1/60 sec . The differences in blur are completely due to the differences in the direction of move- ment . Movement toward , far right , or directly away from the camera always produces less blur than movement across the picture plane , near right . The center picture , with the figure moving diagonally . shows an intermediate effect . So if lighting conditions or other factors force you to use a slower than nor- mal shutter speed , use a head - on rather than side view of the action if you want to reduce blur .
Creating blur :
Sometimes an impression or inter- pretation of the subject is more interesting than a straight record .
Camera movement :
Most shutters have a B - setting , so by using a tripod , you can give long exposures necessary for night scenes such as the bridge , above ( 5 secs at f11 ) . For the interpret- ative version , right , an additional two seconds were given during which the camera was slowly til- ted downward . As a result , every light , following the camera move- ment , described its own vertical line against the black sky .
Creating a blurred surround :
It is not essential for the camera to be stationary when taking a photograph . The motorcyclist , right , was taken from the back of a moving vehicle . The shutter speed was only 1/60 sec , but because the motorcycle was trav- elling at the same speed as the vehicle it has recorded on the film as if it were stationary . The sur- roundings rushing by , particularly at the edges of the picture , create a blurred impression of speed . Like all the pictures shown here , this result is possible with quite a sim- ple camera . Later we will be trying similar effects by using a zoom lens ( see p . 99 ) or by " panning " the camera ( see p . 116 ) .
Assignment : exploring blur and movement
Select a scene containing subjects moving at different speeds and in various direc- tions sports event is ideal ) . Take four pictures :
A. With the shutter set for the fastest time the conditions will allow .
B. With the shutter set at 1/8 sec .
C. With the shutter set at 1 sec .
D. With the shutter set at 1/8 sec again .. but during exposure shifting the camera smoothly in the same direction as the general flow of subject movement .
Select the picture you think is most interesting .
Shutter speed and blur
A camera with a range of shutter speeds helps you to give correct exposure under all kinds of lighting conditions and , just as important , it allows you to choose whether movement will record " frozen " or blurred . A stationary subject photographed with the camera supported on a tripod will appear the same at any shutter speed . But if your subject is moving ( or if you are holding the camera unsteadily ) , different shutter speeds will produce quite different results .
As we have seen the shutter speed deter- mines the length of time that the film is exposed to the image . So the slower the shutter speed , the greater the blur created by subject movement . The exact effect depends on how fast the subject is moving in relation to you , how near you are to the subject , and whether the movement is side - on or directly toward the camera . A fast shutter speed is most likely to record all movement as if stationary .
Some photographers use the fastest shut- ter speeds to avoid recording accidental camera movement , but this can destroy any sense of action . With slower shutter speeds you can achieve many kinds of atmospheric effects , through diffusion and blur .
Supporting the camera :
Different shutter speeds not only freeze or blur subject movement but also suppress or exaggerate any movement of the camera during exposure . For most photo- graphs you need to keep the camera absolutely still ( this way stationary subjects appear without blur ) . Shutter speeds of 1/250 sec or faster rarely show camera shake , provided you are standing still . 1/125 sec is also safe , but remember to depress the shutter release gently - don't just jab it . For slower speeds you really need to provide extra support for your camera . Press your elbows into your waist , use your knee or , bet- ter still , the ground or a table as a base . Sometimes you can press the camera hard against a wall , or something similar , which will give sufficient support for longer ex- posure of 1 sec or so . But for the best results use an adjustable tri- pod , below , and a screw - in cable release for the shutter . Provided the ground is firm you can then safely make long exposures .
Shutter speed and subject movement :
The cyclists were moving at the same speed in each of these three pictures , but the exposures were 1/30 sec . right , 1/125 sec . below left , and 1/500 sec . below right . You can see how the fastest shut- ter setting freezes the action - the image remains on the film so brief- ly that no movement has time to record . The slowest , at 1/30 sec . has blurred the group of cyclists , separating them from their back- ground and creating a strong im- pression of speed . At 1/125 sec there is more detail and only the fastest moving elements - the outer spokes of the wheels show blur although the sense of action is still present .
Blur and direction of movement :
Unlike the pictures of the cyclists opposite , all three pictures here were taken with the same shutter setting 1/60 sec . The differences in blur are completely due to the differences in the direction of move- ment . Movement toward , far right , or directly away from the camera always produces less blur than movement across the picture plane , near right . The center picture , with the figure moving diagonally . shows an intermediate effect . So if lighting conditions or other factors force you to use a slower than nor- mal shutter speed , use a head - on rather than side view of the action if you want to reduce blur .
Creating blur :
Sometimes an impression or inter- pretation of the subject is more interesting than a straight record .
Camera movement :
Most shutters have a B - setting , so by using a tripod , you can give long exposures necessary for night scenes such as the bridge , above ( 5 secs at f11 ) . For the interpret- ative version , right , an additional two seconds were given during which the camera was slowly til- ted downward . As a result , every light , following the camera move- ment , described its own vertical line against the black sky .
Creating a blurred surround :
It is not essential for the camera to be stationary when taking a photograph . The motorcyclist , right , was taken from the back of a moving vehicle . The shutter speed was only 1/60 sec , but because the motorcycle was trav- elling at the same speed as the vehicle it has recorded on the film as if it were stationary . The sur- roundings rushing by , particularly at the edges of the picture , create a blurred impression of speed . Like all the pictures shown here , this result is possible with quite a sim- ple camera . Later we will be trying similar effects by using a zoom lens ( see p . 99 ) or by " panning " the camera ( see p . 116 ) .
Assignment : exploring blur and movement
Select a scene containing subjects moving at different speeds and in various direc- tions sports event is ideal ) . Take four pictures :
A. With the shutter set for the fastest time the conditions will allow .
B. With the shutter set at 1/8 sec .
C. With the shutter set at 1 sec .
D. With the shutter set at 1/8 sec again .. but during exposure shifting the camera smoothly in the same direction as the general flow of subject movement .
Select the picture you think is most interesting .
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