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Local control of contrast
One advantage of variable contrast paper is that you can alter the contrast of different parts of the same print . This is useful when , for example , part of the picture is in deep cast shadow and the rest in harsh sunlight . The sunlit area needs soft grade paper , but if you shade to reveal some detail in the shadow this may record unnaturally gray and flat . The problem is solved , as shown below , by exposing the shadow area only through a high contrast filter ( such as a number 3 filter ) , then changing to a low contrast filter ( such as a number 1 filter ) to print - in the harshly lit part . This technique is also useful for boosting the contrast of sky areas where overexposure on the negative has merged clouds and blue sky .
Another way of altering contrast over a small central part of the print is to shade- out this area with a dodger during the main exposure , then print it in again through a hole in a card with a different filter in place . You can even tape a gelatin filter over the actual hole . With experience you can use shaped filters attached to wire as dodgers , changing contrast and lightening the print at the same time .
The makers of variable contrast papers sell a simple calculator showing how much exposure is affected when changing from one filter to another . However , variable con- trast papers are unlikely to replace graded papers , partly because of the bother of handling filters . In addition , a good print on a graded paper is of slightly better quality than the same negative printed on variable contrast paper .
Using variable contrast paper
1. Estimate the contrast grade needed for the shadowed zone . Using the appropriate filter on the enlarger , make a test strip of varying exposure times across the shadowed area .
2. Decide the grade for the bright area . Change to this filter and make another test strip , this time for the sunlit area . From the two processed test strips estimate the required exposure times for each area .
3. Using a full sheet of paper , give the correct exposure for the shadowed area through its filter . Shade the light area as much as possible , using a piece of card or a dodger .
4. Change to the other filter and print - in the sunlit part , giving the exposure time your second test strip showed to be correct .
Improving local contrast
Subjects like the scene below bene- fit from variable contrast printing . Exposed at low contrast , shadows were flat , below left : at high con-trast , the window was harsh . bottom left . For the final print . below right , the interior was ex- posed at high contrast , the window printed - in at low contrast .
Local control of contrast
One advantage of variable contrast paper is that you can alter the contrast of different parts of the same print . This is useful when , for example , part of the picture is in deep cast shadow and the rest in harsh sunlight . The sunlit area needs soft grade paper , but if you shade to reveal some detail in the shadow this may record unnaturally gray and flat . The problem is solved , as shown below , by exposing the shadow area only through a high contrast filter ( such as a number 3 filter ) , then changing to a low contrast filter ( such as a number 1 filter ) to print - in the harshly lit part . This technique is also useful for boosting the contrast of sky areas where overexposure on the negative has merged clouds and blue sky .
Another way of altering contrast over a small central part of the print is to shade- out this area with a dodger during the main exposure , then print it in again through a hole in a card with a different filter in place . You can even tape a gelatin filter over the actual hole . With experience you can use shaped filters attached to wire as dodgers , changing contrast and lightening the print at the same time .
The makers of variable contrast papers sell a simple calculator showing how much exposure is affected when changing from one filter to another . However , variable con- trast papers are unlikely to replace graded papers , partly because of the bother of handling filters . In addition , a good print on a graded paper is of slightly better quality than the same negative printed on variable contrast paper .
Using variable contrast paper
1. Estimate the contrast grade needed for the shadowed zone . Using the appropriate filter on the enlarger , make a test strip of varying exposure times across the shadowed area .
2. Decide the grade for the bright area . Change to this filter and make another test strip , this time for the sunlit area . From the two processed test strips estimate the required exposure times for each area .
3. Using a full sheet of paper , give the correct exposure for the shadowed area through its filter . Shade the light area as much as possible , using a piece of card or a dodger .
4. Change to the other filter and print - in the sunlit part , giving the exposure time your second test strip showed to be correct .
Improving local contrast
Subjects like the scene below bene- fit from variable contrast printing . Exposed at low contrast , shadows were flat , below left : at high con-trast , the window was harsh . bottom left . For the final print . below right , the interior was ex- posed at high contrast , the window printed - in at low contrast .
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