تويت
التصوير الفوتوغرافي الحديث
الجزء الأول - تصوير فلاش
ملء الفلاش
FLASH FILL - IN
Flash is used a great deal in combination with daylight or sunlight to provide more balanced lighting . Bright sunlight , by itself , produces too great a brightness range for many photographic subjects . The brightness of the highlights in an average sunlit scene may be so high that if the film is exposed to record them properly , the shadows will be badly underexposed and lose practically all detail . If you want to get detail in such shadow areas as well as in the highlights , you must build up the illumination of the shadow . This can be done with flash .
The use of flash for filling in shadows created by strong sunlight is called synchro - sun flash or fill - in flash . For the student photographer , it will find its greatest usefulness in outdoor pictures where a subject's face is in shadow while the scene as a whole is brilliantly lit by the direct rays of the sun .
It is important to get the right amount of light into the shadows for best results . If too strong a flash fill - in is used , the shadows may become lighter than the highlights and the effect of the sunlight will disappear . A picture made this way will often look like a night shot . For most natural appearing pictures , the fill - in flash should have from 2 to 4 the brightness of the sun if you use black - and - white film ; from 2/3 to ½ for color film . In Figure 21 , the fill - in flash was quite weak so as to retain the dramatic effect of the backlighting . In Figure 22 , the fill - in flash was much stronger , so that the shadows are well illuminated but not to the point of equalling the main light - the sun .
Figure 21 This subject calls for a fill - in of minimum strength . Photo by S. J. Silverstein
Figure 22 In this type of picture , the fill - in flash is strong . short of the point where it overcomes the highlights created by the sun .
CORRECT EXPOSURE FOR FILL - IN FLASH . Since the fill - in flash is to be used only to lighten the shadows , the main light source is the sun . When more than one light source is used , the main light always determines the exposure . Our first step , therefore , is to determine the basic exposure in sunlight . Let us say our reading on a sunlit portion of the scene suggests a setting of 1/125 second at // 16 . First , we must find where our flashgun should be placed so its light will equal the intensity of the sunlight . We can then reduce the intensity of the flash fill by covering the flash with a handkerchief or by moving it further from the subject .
You will recall that we can find the number of feet the flash should be from . the subject by dividing the guide number by the f / number . For example , let us say the number is 160. If we divide the guide number by f / 16 , we get 10 . This tells us that at 10 feet the sunlight and flash will be equal in intensity . But since we want the flash fill to be only ½ to 4 as strong as the sunlight , we must reduce the intensity of the flash . We can do this by draping a handkerchief over the flash attachment or by moving the flashgun back from the subject .
Remember , light intensity diminishes as the square of the distance . If we want to cut the light intensity by one - half , we must move the light a little less than 1½ times the calculated distance from the subject ( 1.4 times is the exact figure ) . If you don't want to move the camera back that far , drape a handkerchief in front of the lamp , or move the lamp back by using an extension cord .
الجزء الأول - تصوير فلاش
ملء الفلاش
FLASH FILL - IN
Flash is used a great deal in combination with daylight or sunlight to provide more balanced lighting . Bright sunlight , by itself , produces too great a brightness range for many photographic subjects . The brightness of the highlights in an average sunlit scene may be so high that if the film is exposed to record them properly , the shadows will be badly underexposed and lose practically all detail . If you want to get detail in such shadow areas as well as in the highlights , you must build up the illumination of the shadow . This can be done with flash .
The use of flash for filling in shadows created by strong sunlight is called synchro - sun flash or fill - in flash . For the student photographer , it will find its greatest usefulness in outdoor pictures where a subject's face is in shadow while the scene as a whole is brilliantly lit by the direct rays of the sun .
It is important to get the right amount of light into the shadows for best results . If too strong a flash fill - in is used , the shadows may become lighter than the highlights and the effect of the sunlight will disappear . A picture made this way will often look like a night shot . For most natural appearing pictures , the fill - in flash should have from 2 to 4 the brightness of the sun if you use black - and - white film ; from 2/3 to ½ for color film . In Figure 21 , the fill - in flash was quite weak so as to retain the dramatic effect of the backlighting . In Figure 22 , the fill - in flash was much stronger , so that the shadows are well illuminated but not to the point of equalling the main light - the sun .
Figure 21 This subject calls for a fill - in of minimum strength . Photo by S. J. Silverstein
Figure 22 In this type of picture , the fill - in flash is strong . short of the point where it overcomes the highlights created by the sun .
CORRECT EXPOSURE FOR FILL - IN FLASH . Since the fill - in flash is to be used only to lighten the shadows , the main light source is the sun . When more than one light source is used , the main light always determines the exposure . Our first step , therefore , is to determine the basic exposure in sunlight . Let us say our reading on a sunlit portion of the scene suggests a setting of 1/125 second at // 16 . First , we must find where our flashgun should be placed so its light will equal the intensity of the sunlight . We can then reduce the intensity of the flash fill by covering the flash with a handkerchief or by moving it further from the subject .
You will recall that we can find the number of feet the flash should be from . the subject by dividing the guide number by the f / number . For example , let us say the number is 160. If we divide the guide number by f / 16 , we get 10 . This tells us that at 10 feet the sunlight and flash will be equal in intensity . But since we want the flash fill to be only ½ to 4 as strong as the sunlight , we must reduce the intensity of the flash . We can do this by draping a handkerchief over the flash attachment or by moving the flashgun back from the subject .
Remember , light intensity diminishes as the square of the distance . If we want to cut the light intensity by one - half , we must move the light a little less than 1½ times the calculated distance from the subject ( 1.4 times is the exact figure ) . If you don't want to move the camera back that far , drape a handkerchief in front of the lamp , or move the lamp back by using an extension cord .
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