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مبادئ الإضاءة ..
إضاءة خارجية
OUTDOOR LIGHTING
For a more systematic discussion of the subject of lighting , we will separate it into two major categories - outdoor lighting and indoor lighting . Everything we have said up to this point applies equally well to both indoor and sunlight and artificial light , but from now on we will make these distinctions as an aid to our further detailed study . You must , however , bear in mind that the actual application of some of the principles we will formulate will apply to all categories even though we may state them under only one heading . We will start with outdoor lighting .
In our discussion of outdoor lighting , we will , for the time being , confine ourselves to daylight - that is , the light of the sun . Man - made lighting such as we encounter on a city street at night will be reserved for a later Assignment .
Lighting may be categorized in quite a number of different ways , but since photographers frequently refer to light by its direction , we will use that classification here . We will make the following four major classifications :
1. Front lighting
2. 45 - degree side lighting
3. 90 - degree side lighting ( this is also called full side lighting )
4. Backlighting
FRONT LIGHTING
The most obvious aspect of front lighting is its lack of shadows . This may or may not be an advantage , depending upon the subject and the treatment you wish to accord it . Front lighting is usually flat lighting in that there are no shadows to speak of . If the subject itself has a good deal of modeling , and by that we mean variations in contour and shape , the addition of shadows may be unnecessary to give faithful reproduction , and front lighting may be quite adequate . If the subject has a good deal of color variation , for example , this variation in color may produce all the separation of areas that is required for the color photographer .
Since the color photographer requires much less lighting contrast , he need not rely so much on shadows to give him separation of tones and planes and can , instead , use variation in color to provide the same end result . Similarly , outdoor landscapes and pictures with good perspective , either linear or aerial , may be successfully photographed with front lighting because the all important element of the separation of planes or the imparting of movement can be achieved without reliance on cast shadows .
Outdoor portraits present much more of a problem with this type of lighting . If the lighting is high , the eyes are thrown into deep shadow so that become dull and lifeless . The nose casts a strong downward shadow , exaggerating its length . If the sun is low enough so that the effects are not too noticeable , the subject is almost certain to squint badly when faced with the direct glare of the sun . All these , of course , produce very poor portraits , except in those rare instances when highly dramatic results are desired . Figures 17 and 18 illustrate the incorrect and correct use of front lighting for portraiture - in Figure 17 , the eyes are buried and the nose shadow is very disturbing , while in Figure 18 , the eyes are properly illuminated and the shadows are not objectionable .
Figure 17 Here is the result of having the main light too high . The eyes are in deep shadow , and the shadow from the nose is too long .
Figure 18 Here is the same model as in Figure 17 with the main light correctly placed .
Front lighting is called flat lighting because the shadows created by this type of lighting are either very small or non - existent . As a result , the subject seems to have no depth - in other words , it is flat . However , front lighting may still be used quite successfully for outdoor portraits under two rather special circumstances .
First , if the subject is quite old so that the face is deeply wrinkled , or if he has deeply etched character lines , even front lighting may not be flat enough to eliminate all shadows created by the deeply textured surface of the skin . In these cases , front lighting may be used if desired and may prove an actual advantage if you want to minimize the facial wrinkles .
Second , in the photography of children and of young girls , there may be times when you want completely shadowless lighting so as to capture the maximum possible delicacy of tone gradation and modeling in the face . In these cases , you can use front lighting and rely on perfect exposure and careful printing to retain this delicacy .
45 - DEGREE SIDE LIGHTING
This is the photographer's standby - his golden mean , his reference standard . It is a good safe lighting for practically everything because it avoids extremes . The great majority of photographs are made with 45 - degree lighting - or at least a reasonably close approximation to it .
The shadows cast by a light source coming at an angle of approximately 45 - degrees are strong enough to provide good modeling and will separate planes and surfaces whether the subject is a portrait , a building or a landscape . Shadows look natural so that surface texture also looks natural and yet reasonably prominent . ( We will have much more to say about the photography of textured surfaces later in this Assignment . )
For portraits outdoors , we generally want the light source not only at 45⁰ to either side of the subject , but also at about 45 ° above the subject . This 45 ° -45 ° lighting gives good modeling , not only laterally , but vertically as well and is , therefore , a favorite among portrait photographers for both indoor and outdoor shooting . Another advantage of the higher angle is that the light source does not hit the eyes of the subject with nearly as much glare as a lower angle so that the eyes do not take on the strained expression which is so common with outdoor portraits taken in strong sunlight .
90 - DEGREE SIDE LIGHTING
This is one of the more dramatic lightings at the disposal of the photographer . It must be used with skill and discretion . Because the lighting comes from so extreme an angle , most of the subject is in shadow , and it is not easy to make an interesting picture of a subject which is largely in shadow . When the photographer succeeds in doing so in spite of its difficulty , he usually has a very effective picture , and that is why this type of lighting should be mastered .
The light coming from so strong an angle just skims the surface of the subject , picking out only those areas which extend outward from it and bathing them in strong light . These small , strongly lighted areas contrast brilliantly with the much darker background material . If a subject of this kind is well chosen and printed for deep , rich blacks so that the whole effect is low key , the result can be brilliantly dramatic .
Because strongly angled light skims the surface , it is often called skim light or rim light by photographers .
The long shadows cast by strongly angled light exaggerate the texture of any object they strike . The texture of a surface is composed or produced by the tiny hills , valleys and irregularities in the surface . If these hills and valleys are very tiny and quite close to each other , the surface is smooth and even textured . On the other hand , if the hills and valleys are relatively large , the surface is rough . With strong side lighting , these hills or bumps in a surface throw long shadows , and these excessively long shadows cause the surface irregularities to appear much larger than they really are . The result is a strongly exaggerated surface texture .
It is for that reason that strongly angled lighting is also called texture lighting . The photographer often uses such lighting in the studio to bring out the texture of a commodity he is photographing , but it can also be used outdoors in sunlight if the picture calls for that type of treatment . Figure 19 is a good example of texture lighting to give importance to an otherwise very ordinary beach scene .
Figure 19 How strong , low - angle lighting accentuates the texture of sand . Photo by G. Maling
In outdoor portraiture , texture lighting is usually avoided because exaggerated facial texture is almost always undesirable . However , there are times . when it can be used to give added strength and virility to the portrait of someone who has spent most of his life outdoors and whose face is expected to show the weather - beaten effects of such exposure .
BACKLIGHTING
Backlighting is a rather broad term . If the light comes from anywhere in back of the subject , we consider it to be backlighted whether the light is high or low , directly in back or far to the side of the subject . Backlighting can be even more dramatic than extreme side lighting . It can produce the same dramatic effect of low key , deep poorly illuminated shadows , and sparse but highly significant highlights which serve more as outlines of important subject areas than as sources of illumination .
In a backlighted subject , the shadows move forward , toward the observer giving a strongly heightened effect of movement and force . This is so important a factor in the photography of commercial products in the studio that many . photographers specializing in this kind of work invariably place a spotlight in back of the product they are photographing so as to produce long and prominent forward moving shadows . By this means , they impart added depth and perspective and enhance the dramatic effect which is so important in this type of photography . We will discuss this use of backlighting later in this Assignment when we come to the subject of indoor lighting .
Outdoors , where the sun is the sole source of illumination , positioning it in back of the subject throws the subject into deep silhouette . This can be very effective where the main subject carries no important detail so that it can be treated very broadly . Sunrises and sunsets are of this nature , and Figures 20 and 21 illustrate how some very unimportant foreground material can be given considerable strength and prominence by throwing them into deep silhouette with the sun near the horizon in an exciting cloud formation .
Another silhouette effect is shown in Figure 22 , but this time , since there is no strong sky pattern to create an effective picture , the interest is supplied by the strong shadow pattern on the snow .
Giving a backlighted subject the correct exposure can be quite a problem , since the photographer has to make up his mind just how much detail he wants in his main subject which is illuminated only by reflected light and how much brilliance or contrast he wants in his highlight areas or areas of specular reflection . If the basic idea is to show the foreground material in complete silhouette , as in a sunset , take your meter reading of the sky and expose accordingly . With this type of picture , the sun itself must be very low on the horizon so that it is no more than a red ball , or it must be shaded behind clouds , trees , or other objects . If the sun is reasonably high and it is not shaded , you will get very little more than a bright glare for the sun and then empty sky . However , if you have some dramatic clouds and the sun is not directly in the camera view or else it is shaded from the camera , you should get a good exciting sunset effect .
If you are not shooting for the strong silhouette effect , and want some detail in your foreground subjects , take a meter reading of your main subjects , but stop down three full stops from the normal meter reading and you will get a minimum amount of detail in the subject material . These outline the two extremes of exposure . With some practice , you should be able to use good judgment as to which exposure between these two extremes will give you the exact result you want .
Since you are operating at the minimum exposure point for your main subject , exposure is quite critical and only a slight difference in exposure will make quite an important difference in the detail in your shadow area . It is best , therefore , to bracket your exposures . For black - and - white film or for negative color film starting with the shortest exposure , increase exposure one full stop for a total of at least three different exposures . One of these should be about what you want , and if it isn't exactly so , you can still get a perfect print by proper printing control methods . If you use positive color film , your exposure latitude is considerably less and you should bracket exposures by half stops instead of full stops .
The subject of exposure backlighted subjects is covered in more detail in the Assignment on exposure and exposure meters .
Figure 20 An undramatic , ordinary beach scene printed normally .
مبادئ الإضاءة ..
إضاءة خارجية
OUTDOOR LIGHTING
For a more systematic discussion of the subject of lighting , we will separate it into two major categories - outdoor lighting and indoor lighting . Everything we have said up to this point applies equally well to both indoor and sunlight and artificial light , but from now on we will make these distinctions as an aid to our further detailed study . You must , however , bear in mind that the actual application of some of the principles we will formulate will apply to all categories even though we may state them under only one heading . We will start with outdoor lighting .
In our discussion of outdoor lighting , we will , for the time being , confine ourselves to daylight - that is , the light of the sun . Man - made lighting such as we encounter on a city street at night will be reserved for a later Assignment .
Lighting may be categorized in quite a number of different ways , but since photographers frequently refer to light by its direction , we will use that classification here . We will make the following four major classifications :
1. Front lighting
2. 45 - degree side lighting
3. 90 - degree side lighting ( this is also called full side lighting )
4. Backlighting
FRONT LIGHTING
The most obvious aspect of front lighting is its lack of shadows . This may or may not be an advantage , depending upon the subject and the treatment you wish to accord it . Front lighting is usually flat lighting in that there are no shadows to speak of . If the subject itself has a good deal of modeling , and by that we mean variations in contour and shape , the addition of shadows may be unnecessary to give faithful reproduction , and front lighting may be quite adequate . If the subject has a good deal of color variation , for example , this variation in color may produce all the separation of areas that is required for the color photographer .
Since the color photographer requires much less lighting contrast , he need not rely so much on shadows to give him separation of tones and planes and can , instead , use variation in color to provide the same end result . Similarly , outdoor landscapes and pictures with good perspective , either linear or aerial , may be successfully photographed with front lighting because the all important element of the separation of planes or the imparting of movement can be achieved without reliance on cast shadows .
Outdoor portraits present much more of a problem with this type of lighting . If the lighting is high , the eyes are thrown into deep shadow so that become dull and lifeless . The nose casts a strong downward shadow , exaggerating its length . If the sun is low enough so that the effects are not too noticeable , the subject is almost certain to squint badly when faced with the direct glare of the sun . All these , of course , produce very poor portraits , except in those rare instances when highly dramatic results are desired . Figures 17 and 18 illustrate the incorrect and correct use of front lighting for portraiture - in Figure 17 , the eyes are buried and the nose shadow is very disturbing , while in Figure 18 , the eyes are properly illuminated and the shadows are not objectionable .
Figure 17 Here is the result of having the main light too high . The eyes are in deep shadow , and the shadow from the nose is too long .
Figure 18 Here is the same model as in Figure 17 with the main light correctly placed .
Front lighting is called flat lighting because the shadows created by this type of lighting are either very small or non - existent . As a result , the subject seems to have no depth - in other words , it is flat . However , front lighting may still be used quite successfully for outdoor portraits under two rather special circumstances .
First , if the subject is quite old so that the face is deeply wrinkled , or if he has deeply etched character lines , even front lighting may not be flat enough to eliminate all shadows created by the deeply textured surface of the skin . In these cases , front lighting may be used if desired and may prove an actual advantage if you want to minimize the facial wrinkles .
Second , in the photography of children and of young girls , there may be times when you want completely shadowless lighting so as to capture the maximum possible delicacy of tone gradation and modeling in the face . In these cases , you can use front lighting and rely on perfect exposure and careful printing to retain this delicacy .
45 - DEGREE SIDE LIGHTING
This is the photographer's standby - his golden mean , his reference standard . It is a good safe lighting for practically everything because it avoids extremes . The great majority of photographs are made with 45 - degree lighting - or at least a reasonably close approximation to it .
The shadows cast by a light source coming at an angle of approximately 45 - degrees are strong enough to provide good modeling and will separate planes and surfaces whether the subject is a portrait , a building or a landscape . Shadows look natural so that surface texture also looks natural and yet reasonably prominent . ( We will have much more to say about the photography of textured surfaces later in this Assignment . )
For portraits outdoors , we generally want the light source not only at 45⁰ to either side of the subject , but also at about 45 ° above the subject . This 45 ° -45 ° lighting gives good modeling , not only laterally , but vertically as well and is , therefore , a favorite among portrait photographers for both indoor and outdoor shooting . Another advantage of the higher angle is that the light source does not hit the eyes of the subject with nearly as much glare as a lower angle so that the eyes do not take on the strained expression which is so common with outdoor portraits taken in strong sunlight .
90 - DEGREE SIDE LIGHTING
This is one of the more dramatic lightings at the disposal of the photographer . It must be used with skill and discretion . Because the lighting comes from so extreme an angle , most of the subject is in shadow , and it is not easy to make an interesting picture of a subject which is largely in shadow . When the photographer succeeds in doing so in spite of its difficulty , he usually has a very effective picture , and that is why this type of lighting should be mastered .
The light coming from so strong an angle just skims the surface of the subject , picking out only those areas which extend outward from it and bathing them in strong light . These small , strongly lighted areas contrast brilliantly with the much darker background material . If a subject of this kind is well chosen and printed for deep , rich blacks so that the whole effect is low key , the result can be brilliantly dramatic .
Because strongly angled light skims the surface , it is often called skim light or rim light by photographers .
The long shadows cast by strongly angled light exaggerate the texture of any object they strike . The texture of a surface is composed or produced by the tiny hills , valleys and irregularities in the surface . If these hills and valleys are very tiny and quite close to each other , the surface is smooth and even textured . On the other hand , if the hills and valleys are relatively large , the surface is rough . With strong side lighting , these hills or bumps in a surface throw long shadows , and these excessively long shadows cause the surface irregularities to appear much larger than they really are . The result is a strongly exaggerated surface texture .
It is for that reason that strongly angled lighting is also called texture lighting . The photographer often uses such lighting in the studio to bring out the texture of a commodity he is photographing , but it can also be used outdoors in sunlight if the picture calls for that type of treatment . Figure 19 is a good example of texture lighting to give importance to an otherwise very ordinary beach scene .
Figure 19 How strong , low - angle lighting accentuates the texture of sand . Photo by G. Maling
In outdoor portraiture , texture lighting is usually avoided because exaggerated facial texture is almost always undesirable . However , there are times . when it can be used to give added strength and virility to the portrait of someone who has spent most of his life outdoors and whose face is expected to show the weather - beaten effects of such exposure .
BACKLIGHTING
Backlighting is a rather broad term . If the light comes from anywhere in back of the subject , we consider it to be backlighted whether the light is high or low , directly in back or far to the side of the subject . Backlighting can be even more dramatic than extreme side lighting . It can produce the same dramatic effect of low key , deep poorly illuminated shadows , and sparse but highly significant highlights which serve more as outlines of important subject areas than as sources of illumination .
In a backlighted subject , the shadows move forward , toward the observer giving a strongly heightened effect of movement and force . This is so important a factor in the photography of commercial products in the studio that many . photographers specializing in this kind of work invariably place a spotlight in back of the product they are photographing so as to produce long and prominent forward moving shadows . By this means , they impart added depth and perspective and enhance the dramatic effect which is so important in this type of photography . We will discuss this use of backlighting later in this Assignment when we come to the subject of indoor lighting .
Outdoors , where the sun is the sole source of illumination , positioning it in back of the subject throws the subject into deep silhouette . This can be very effective where the main subject carries no important detail so that it can be treated very broadly . Sunrises and sunsets are of this nature , and Figures 20 and 21 illustrate how some very unimportant foreground material can be given considerable strength and prominence by throwing them into deep silhouette with the sun near the horizon in an exciting cloud formation .
Another silhouette effect is shown in Figure 22 , but this time , since there is no strong sky pattern to create an effective picture , the interest is supplied by the strong shadow pattern on the snow .
Giving a backlighted subject the correct exposure can be quite a problem , since the photographer has to make up his mind just how much detail he wants in his main subject which is illuminated only by reflected light and how much brilliance or contrast he wants in his highlight areas or areas of specular reflection . If the basic idea is to show the foreground material in complete silhouette , as in a sunset , take your meter reading of the sky and expose accordingly . With this type of picture , the sun itself must be very low on the horizon so that it is no more than a red ball , or it must be shaded behind clouds , trees , or other objects . If the sun is reasonably high and it is not shaded , you will get very little more than a bright glare for the sun and then empty sky . However , if you have some dramatic clouds and the sun is not directly in the camera view or else it is shaded from the camera , you should get a good exciting sunset effect .
If you are not shooting for the strong silhouette effect , and want some detail in your foreground subjects , take a meter reading of your main subjects , but stop down three full stops from the normal meter reading and you will get a minimum amount of detail in the subject material . These outline the two extremes of exposure . With some practice , you should be able to use good judgment as to which exposure between these two extremes will give you the exact result you want .
Since you are operating at the minimum exposure point for your main subject , exposure is quite critical and only a slight difference in exposure will make quite an important difference in the detail in your shadow area . It is best , therefore , to bracket your exposures . For black - and - white film or for negative color film starting with the shortest exposure , increase exposure one full stop for a total of at least three different exposures . One of these should be about what you want , and if it isn't exactly so , you can still get a perfect print by proper printing control methods . If you use positive color film , your exposure latitude is considerably less and you should bracket exposures by half stops instead of full stops .
The subject of exposure backlighted subjects is covered in more detail in the Assignment on exposure and exposure meters .
Figure 20 An undramatic , ordinary beach scene printed normally .
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