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المحيط الساطع .. مصدر الضوء .. كيفية التقاط وتطوير الصور الملونة
BRIGHT SURROUNDINGS
The sea , snow , light - coloured sand and other bright , open settings can make a marked difference to the lighting . All of them act as reflectors , bouncing natural light back upwards , filling in shadows and generally raising the bright- ness level . Because they reflect the sky and sun , their appearance changes drastically with variations in the weather . The contrast , for example , can range from extremely low , on a dull , overcast day , to very high , if the sun is in front of the camera .
-- Without care , bright surroundings can cause difficulties with exposure . If , for instance , the camera's TTL meter reads a large area of white a snowbank or bright surf at the seashore - the photograph will inevitably be under- exposed . In a direct reading like this , the meter averages , and produces a setting that will reproduce what lies in front of it as a mid - tone . Avoiding this is largely a matter of commonsense . With a TTL meter , either point the camera to a medium - toned part of the scene in order to get an overall reading , or make a mental adjustment for the reading directly off the snow , bright sand or water .
ABOVE AND LEFT Snow can easily fool a camera's TTL exposure metering system into underexposure ( above ) . It is easy for the TTL system to suggest an exposure that could be as many as 2½ stops below the correct reading ( say , 1 / 60sec at f11 rather than 1 / 60sec at f5.6 or even f4 ) . Using a hand - held light meter can solve this problem or , alternatively , make use of the spot metering systems found in many of today's SLRs - they take a light reading from a very small area of the scene . The idea is to find the ideal brightness in a scene , and take the spot reading from there . If a shortage of suitable equipment or circumstances dictate , take an exposure reading from the most important subject in the scene .
Simply think how dark or light you would like the bright surface to appear ; if | sunlit snow , it will probably look best if white but not completely washed - out , still showing some texture . This level of whiteness is about 2½ stops higher than average , so open up the lens aperture by about this amount from the direct TTL reading . Normal sand would normally be less bright than this perhaps one stop brighter than average . Mainly , this is a matter of personal judgement . If you have a handheld meter , follow its recommendations without adjustment ; it measures the light , not the surfaces . Note that the general level of brightness is higher in these surroundings , often by about one stop , so do not be surprised if your camera settings are different from what you are used to in more normal landscapes .
Because reflective surroundings react to changes in the natural light , one of the great pleasures in photographing them is the variety of image , and it is shortsighted to think that there is only one optimum lighting condition . Cer- tainly , low , raking sunlight brings out texture in sand ripples and snow , par- ticularly if the sun is to one side or in front of the camera , but even flat lighting produces its own special visual appeal . Be careful , however , if most of the picture is in shadow under an open , clear sky because the extra brightness of the snow or sand will throw much of the blueness of the sky into the shadow area , and skin tones in particular will look strange and cold .
BELOW A hand - held light meter such as this Gossen Lunasix can be used either for incident or reflected light readings , and can be fitted with various accessory attachments .
ABOVE AND LEFT Both sand and sea can make a marked difference to lighting . Sand may be one stop brighter than average , while reflected light from the sea can result in severe underexposure .
BRIGHT SURROUNDINGS
The sea , snow , light - coloured sand and other bright , open settings can make a marked difference to the lighting . All of them act as reflectors , bouncing natural light back upwards , filling in shadows and generally raising the bright- ness level . Because they reflect the sky and sun , their appearance changes drastically with variations in the weather . The contrast , for example , can range from extremely low , on a dull , overcast day , to very high , if the sun is in front of the camera .
-- Without care , bright surroundings can cause difficulties with exposure . If , for instance , the camera's TTL meter reads a large area of white a snowbank or bright surf at the seashore - the photograph will inevitably be under- exposed . In a direct reading like this , the meter averages , and produces a setting that will reproduce what lies in front of it as a mid - tone . Avoiding this is largely a matter of commonsense . With a TTL meter , either point the camera to a medium - toned part of the scene in order to get an overall reading , or make a mental adjustment for the reading directly off the snow , bright sand or water .
ABOVE AND LEFT Snow can easily fool a camera's TTL exposure metering system into underexposure ( above ) . It is easy for the TTL system to suggest an exposure that could be as many as 2½ stops below the correct reading ( say , 1 / 60sec at f11 rather than 1 / 60sec at f5.6 or even f4 ) . Using a hand - held light meter can solve this problem or , alternatively , make use of the spot metering systems found in many of today's SLRs - they take a light reading from a very small area of the scene . The idea is to find the ideal brightness in a scene , and take the spot reading from there . If a shortage of suitable equipment or circumstances dictate , take an exposure reading from the most important subject in the scene .
Simply think how dark or light you would like the bright surface to appear ; if | sunlit snow , it will probably look best if white but not completely washed - out , still showing some texture . This level of whiteness is about 2½ stops higher than average , so open up the lens aperture by about this amount from the direct TTL reading . Normal sand would normally be less bright than this perhaps one stop brighter than average . Mainly , this is a matter of personal judgement . If you have a handheld meter , follow its recommendations without adjustment ; it measures the light , not the surfaces . Note that the general level of brightness is higher in these surroundings , often by about one stop , so do not be surprised if your camera settings are different from what you are used to in more normal landscapes .
Because reflective surroundings react to changes in the natural light , one of the great pleasures in photographing them is the variety of image , and it is shortsighted to think that there is only one optimum lighting condition . Cer- tainly , low , raking sunlight brings out texture in sand ripples and snow , par- ticularly if the sun is to one side or in front of the camera , but even flat lighting produces its own special visual appeal . Be careful , however , if most of the picture is in shadow under an open , clear sky because the extra brightness of the snow or sand will throw much of the blueness of the sky into the shadow area , and skin tones in particular will look strange and cold .
BELOW A hand - held light meter such as this Gossen Lunasix can be used either for incident or reflected light readings , and can be fitted with various accessory attachments .
ABOVE AND LEFT Both sand and sea can make a marked difference to lighting . Sand may be one stop brighter than average , while reflected light from the sea can result in severe underexposure .
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