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Modifying the enlarger
You can use several techniques at the en- larging stage to improve prints made from very contrasty or very flat negatives .
The design of the enlarger you are using is important - if it has a condenser system giving harsh spotlight - type illumination , the negative will print harder than if the lighting is more diffused . Placing a diffuser , as ex- plained below , between the lamp and the condenser will effectively lower the contrast . Another , simple way you can reduce con- trast is to fog the printing paper slightly , by very briefly exposing it to light .
To increase contrast on the print use a smaller size lamp in the enlarger . This in- tensifies the beam , as shown below right .
Contrast and enlarger light
Light from a condenser system in the enlarger , top left , is direct . This means that contrast in the negative is brought out . Clear areas of the negative allow the direct light to pass , while denser areas absorb and scatter the light and appear dark .
A diffuser system , below left , passes light which is already fully scattered through the negative . As a result the difference between light and dark areas of the image ( contrast ) is less marked , since dark areas in the negative cannot further scatter the light .
Modifying the light quality
You can make a hard negative print one grade softer in a con- denser enlarger by putting tracing paper in the filter drawer . For the opposite effect put a black card with a small hole cut out just below the lamp . This reduces lamp size and dims the light , but makes lighting quality harder . With both methods , make a test strip to re - assess the exposure for the negative .
Enlarger light sources
Enlargers illuminate the negative by different systems . In one arrange- ment a grainless diffusing disk ( on an enlarger with a color head , a " scatter box " ) diffuses light rays in all directions . The negative is softly and evenly lit. In other en- largers a condenser concentrates direct light through the negative . This system gives a brighter , harder image . Negative scratches are made more obvious , and you may have to adjust the lamp position at maximum size enlargements so as to illuminate the negative evenly .
" Flashing " the print to light
slightly You can reduce the contrast of an excessively hard print , shown above left , by " flashing " fogging the print - before pro- cessing . First expose the image normally to suit subject shadow and mid - tone detail . Then hold tracing paper just below the lens and give the whole print another brief exposure - try giving one tenth of the previous exposure time . After processing highlight detail is improved on the print , as shown above right . Improvement continues in proportion to the fogging exposure time , up to a point when light areas begin to look gray and veiled .
Reminders : Controlling the negative
Film and developer
Choose a developer to suit the film speed . You can modify the quality of the negative by the developer you use . But image graininess is mostly determined by your choice of film . Exposure , type of developer , and development time are secondary factors .
The performance of all film is restricted to a limited tonal range
Film can only respond ac- curately to a limited range of tones in any one subject . Beyond the light or dark ends of this range tones begin to merge and lose detail .
The development time can be altered to compensate for exposure errors
Underexposure is compen- Isated for by overdevelopment , overexposure is compensated by underdevelopment . But the amount of compensation you can give is limited , usually by the increase or reduction in contrast .
Contrast and the density of the negative can be improved by chemicals and by masking
Reducers and intensifiers can remedy over- or under- development and , to a lesser degree , exposure errors .
The enlarger light affects contrast in the print
To increase contrast on the print , change to a condenser enlarger or make the light source smaller . To reduce contrast , diffuse the light or slightly fog the print .
Modifying the enlarger
You can use several techniques at the en- larging stage to improve prints made from very contrasty or very flat negatives .
The design of the enlarger you are using is important - if it has a condenser system giving harsh spotlight - type illumination , the negative will print harder than if the lighting is more diffused . Placing a diffuser , as ex- plained below , between the lamp and the condenser will effectively lower the contrast . Another , simple way you can reduce con- trast is to fog the printing paper slightly , by very briefly exposing it to light .
To increase contrast on the print use a smaller size lamp in the enlarger . This in- tensifies the beam , as shown below right .
Contrast and enlarger light
Light from a condenser system in the enlarger , top left , is direct . This means that contrast in the negative is brought out . Clear areas of the negative allow the direct light to pass , while denser areas absorb and scatter the light and appear dark .
A diffuser system , below left , passes light which is already fully scattered through the negative . As a result the difference between light and dark areas of the image ( contrast ) is less marked , since dark areas in the negative cannot further scatter the light .
Modifying the light quality
You can make a hard negative print one grade softer in a con- denser enlarger by putting tracing paper in the filter drawer . For the opposite effect put a black card with a small hole cut out just below the lamp . This reduces lamp size and dims the light , but makes lighting quality harder . With both methods , make a test strip to re - assess the exposure for the negative .
Enlarger light sources
Enlargers illuminate the negative by different systems . In one arrange- ment a grainless diffusing disk ( on an enlarger with a color head , a " scatter box " ) diffuses light rays in all directions . The negative is softly and evenly lit. In other en- largers a condenser concentrates direct light through the negative . This system gives a brighter , harder image . Negative scratches are made more obvious , and you may have to adjust the lamp position at maximum size enlargements so as to illuminate the negative evenly .
" Flashing " the print to light
slightly You can reduce the contrast of an excessively hard print , shown above left , by " flashing " fogging the print - before pro- cessing . First expose the image normally to suit subject shadow and mid - tone detail . Then hold tracing paper just below the lens and give the whole print another brief exposure - try giving one tenth of the previous exposure time . After processing highlight detail is improved on the print , as shown above right . Improvement continues in proportion to the fogging exposure time , up to a point when light areas begin to look gray and veiled .
Reminders : Controlling the negative
Film and developer
Choose a developer to suit the film speed . You can modify the quality of the negative by the developer you use . But image graininess is mostly determined by your choice of film . Exposure , type of developer , and development time are secondary factors .
The performance of all film is restricted to a limited tonal range
Film can only respond ac- curately to a limited range of tones in any one subject . Beyond the light or dark ends of this range tones begin to merge and lose detail .
The development time can be altered to compensate for exposure errors
Underexposure is compen- Isated for by overdevelopment , overexposure is compensated by underdevelopment . But the amount of compensation you can give is limited , usually by the increase or reduction in contrast .
Contrast and the density of the negative can be improved by chemicals and by masking
Reducers and intensifiers can remedy over- or under- development and , to a lesser degree , exposure errors .
The enlarger light affects contrast in the print
To increase contrast on the print , change to a condenser enlarger or make the light source smaller . To reduce contrast , diffuse the light or slightly fog the print .
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