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الخطوة 5: الإضاءة الاصطناعية / المعدات .. معدات وتقنيات إضافية .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
STEP 5 : ARTIFICIAL LIGHTING / Equipment
With artificial lighting , you have complete control over the direction , quality and strength of the light . You can move light sources around , and diffuse or reflect them . In addition , you can alter the intensity of light to suit the subject , or to match a chosen lens aperture or shutter speed .
Such control enables you to use the lights to create many special effects . But for most purposes you will want to produce lighting that looks natural and does not intrude upon the main subject . This requires great skill and imposes some restrictions on using artificial lighting . For example , normally we are used to seeing one set of shadows , as cast by the sun , not two or three as produced by several lights . And natural lighting is usually cast from above , not below the subject .
Everything you have learned so far about natural lighting quality and direction also applies to artificial lighting . You can decide to use a harsh light source , such as a spot- light , flashbulb or desk lamp , to give lighting quality similar to direct sunlight . Or you can use a photoflood to cast softer illumination which will give lighting comparable to hazy sunlight . With either light source you can produce an effect like overcast daylight by diffusing the light with tracing paper , or by reflecting it off a mat white surface .
Natural and artificial lighting
For most subjects you will want to use artificial lighting to reproduce the effects of natural light . You will only want to create unnatural lighting conditions for special effects . To simulate natural lighting you have to control the position of the lamps and the quality of the lighting very carefully .
The picture , top left , was taken in diffused daylight . Detail is clear on the girl's face and there are no harsh shadows . The picture , bottom left , was taken in artificial lighting , carefully set up to create a similar diffused quality to the natural lighting . Two diffused photofloods were used , one as a main lamp and one to fill - in any shadows . Again , the lighting is constant across the subject and detail is clear and distinct on the image .
Light and surface
To control lighting , you must understand how light changes in quality and direction when it meets a surface . The five main effects are shown below - light is either dif- fused , reflected or absorbed , or sometimes modified by a combina- tion of these changes .
Diffusion
A diffusing material such as trac- ing paper , ground glass , or opal plastic , scatters light passing through it . This changes its quality from hard to soft .
Specular reflection
When you reflect direct light off a glossy light - toned surface , it re- mains harsh and directional . The reflection records as a glare spot .
Diffuse reflection
Reflective , irregular surfaces , such as blotting paper or other textured materials , scatter light . This alters the quality of the light , changing it from hard to soft .
Selective absorption
Smooth gray or colored surfaces absorb some light and reflect the remainder . Colored surfaces reflect selected wavelengths ( see pp . 141-3 ) ; gray surfaces a percentage of all wavelengths .
Absorption
A black surface absorbs most of the incident light falling on it . The light energy is usually turned into heat , so dark - toned subjects or equipment will heat up easily .
Lighting equipment
There are two main kinds of photo- graphic tungsten lighting : spotlights and photofloods . Spotlights are small clear lamps , which give you a concentrated beam of hard light . You can soften the light by diffuse reflection from a mat white sur- face , such as a white lined umbrella ,
or a white wall . You can also pass it through a diffuser , made of gauze or tracing paper . Barn doors and snoots attach to spot- lights to restrict the beam width . A photoflood has a diffused lamp and large mat reflector , and gives you softer , even lighting .
Spotlight and barn doors
Umbrella reflector
Snoot
Gauze diffuser
Home - made diffuser
Photoflood and lighting stand
STEP 5 : ARTIFICIAL LIGHTING / Equipment
With artificial lighting , you have complete control over the direction , quality and strength of the light . You can move light sources around , and diffuse or reflect them . In addition , you can alter the intensity of light to suit the subject , or to match a chosen lens aperture or shutter speed .
Such control enables you to use the lights to create many special effects . But for most purposes you will want to produce lighting that looks natural and does not intrude upon the main subject . This requires great skill and imposes some restrictions on using artificial lighting . For example , normally we are used to seeing one set of shadows , as cast by the sun , not two or three as produced by several lights . And natural lighting is usually cast from above , not below the subject .
Everything you have learned so far about natural lighting quality and direction also applies to artificial lighting . You can decide to use a harsh light source , such as a spot- light , flashbulb or desk lamp , to give lighting quality similar to direct sunlight . Or you can use a photoflood to cast softer illumination which will give lighting comparable to hazy sunlight . With either light source you can produce an effect like overcast daylight by diffusing the light with tracing paper , or by reflecting it off a mat white surface .
Natural and artificial lighting
For most subjects you will want to use artificial lighting to reproduce the effects of natural light . You will only want to create unnatural lighting conditions for special effects . To simulate natural lighting you have to control the position of the lamps and the quality of the lighting very carefully .
The picture , top left , was taken in diffused daylight . Detail is clear on the girl's face and there are no harsh shadows . The picture , bottom left , was taken in artificial lighting , carefully set up to create a similar diffused quality to the natural lighting . Two diffused photofloods were used , one as a main lamp and one to fill - in any shadows . Again , the lighting is constant across the subject and detail is clear and distinct on the image .
Light and surface
To control lighting , you must understand how light changes in quality and direction when it meets a surface . The five main effects are shown below - light is either dif- fused , reflected or absorbed , or sometimes modified by a combina- tion of these changes .
Diffusion
A diffusing material such as trac- ing paper , ground glass , or opal plastic , scatters light passing through it . This changes its quality from hard to soft .
Specular reflection
When you reflect direct light off a glossy light - toned surface , it re- mains harsh and directional . The reflection records as a glare spot .
Diffuse reflection
Reflective , irregular surfaces , such as blotting paper or other textured materials , scatter light . This alters the quality of the light , changing it from hard to soft .
Selective absorption
Smooth gray or colored surfaces absorb some light and reflect the remainder . Colored surfaces reflect selected wavelengths ( see pp . 141-3 ) ; gray surfaces a percentage of all wavelengths .
Absorption
A black surface absorbs most of the incident light falling on it . The light energy is usually turned into heat , so dark - toned subjects or equipment will heat up easily .
Lighting equipment
There are two main kinds of photo- graphic tungsten lighting : spotlights and photofloods . Spotlights are small clear lamps , which give you a concentrated beam of hard light . You can soften the light by diffuse reflection from a mat white sur- face , such as a white lined umbrella ,
or a white wall . You can also pass it through a diffuser , made of gauze or tracing paper . Barn doors and snoots attach to spot- lights to restrict the beam width . A photoflood has a diffused lamp and large mat reflector , and gives you softer , even lighting .
Spotlight and barn doors
Umbrella reflector
Snoot
Gauze diffuser
Home - made diffuser
Photoflood and lighting stand
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