تويت
الصور الفوتوغرافية والصور السلبية المجمعة .. تقنيات الغرف المظلمة المتقدمة .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
Photograms and combined negatives
Photograms are made without using a camera . You simple arrange objects directly on top of light - sensitive paper ( or sheet film ) and make an exposure under the enlarger . Opaque objects appear as sharply defined shapes with hard , line edges . Semi - trans- parent materials give gray tones according to their opacity . A straight photogram gives negative tone values , but you can contact print this on to another sheet of printing paper to create a positive image .
You can construct interesting , new com- compositions by " sandwiching " , that is simultaneously exposing two normal nega- tives , or one normal negative and a photo- gram on sheet film on to printing paper .
Making a direct photogram
The photogram , left , was produced by exposing a sheet of grade 2 bromide paper with dried flowers placed on top . Parts of the flowers not directly in contact with the paper are blurred and unsharp , giving the image a feeling of depth .
When making a photogram , position the enlarger at the top of its column and use the smallest aperture so that it gives a hard light . Make a test strip to find the exposure time that gives a rich black background and makes any translucent objects print gray . Overexposure will blur the edges of the objects because of light spread .
Making a photogram / negative combination
1. Under safelighting arrange the objects on the printing paper . With the safe filter over the enlarger lens , check the shadows they form before making an exposure .
2. Develop the photogram until you can just see the position of the clear areas . Then remove it , rinse and blot off any liquid , and replace the paper under the enlarger .
3. With the safe filter in position set up a negative in the enlarger so that the image combines well with the half - developed photo- gram . Expose , then fully develop and process the paper . The picture below was produced by this technique .
Combining two negatives
Printing two negatives at once , or " sandwiching " , can sometimes create interesting results , particu- larly if the two images are quite simple . The two negatives , right . are of very simple subjects . When they are printed together . below , they produce an effective image that is not confused or com- plicated by too much detail .
To print two negatives at once you must either use a glass nega- tive carrier , or modify other carriers by using a glass slide mount to hold the two negatives firmly so they can be focused together . The negatives should be sand- wiched emulsion sides inward . If the images will only work well the other way around , you must use a small lens aperture to keep both images sharp .
First negative
Second negative
Final print
Photograms and combined negatives
Photograms are made without using a camera . You simple arrange objects directly on top of light - sensitive paper ( or sheet film ) and make an exposure under the enlarger . Opaque objects appear as sharply defined shapes with hard , line edges . Semi - trans- parent materials give gray tones according to their opacity . A straight photogram gives negative tone values , but you can contact print this on to another sheet of printing paper to create a positive image .
You can construct interesting , new com- compositions by " sandwiching " , that is simultaneously exposing two normal nega- tives , or one normal negative and a photo- gram on sheet film on to printing paper .
Making a direct photogram
The photogram , left , was produced by exposing a sheet of grade 2 bromide paper with dried flowers placed on top . Parts of the flowers not directly in contact with the paper are blurred and unsharp , giving the image a feeling of depth .
When making a photogram , position the enlarger at the top of its column and use the smallest aperture so that it gives a hard light . Make a test strip to find the exposure time that gives a rich black background and makes any translucent objects print gray . Overexposure will blur the edges of the objects because of light spread .
Making a photogram / negative combination
1. Under safelighting arrange the objects on the printing paper . With the safe filter over the enlarger lens , check the shadows they form before making an exposure .
2. Develop the photogram until you can just see the position of the clear areas . Then remove it , rinse and blot off any liquid , and replace the paper under the enlarger .
3. With the safe filter in position set up a negative in the enlarger so that the image combines well with the half - developed photo- gram . Expose , then fully develop and process the paper . The picture below was produced by this technique .
Combining two negatives
Printing two negatives at once , or " sandwiching " , can sometimes create interesting results , particu- larly if the two images are quite simple . The two negatives , right . are of very simple subjects . When they are printed together . below , they produce an effective image that is not confused or com- plicated by too much detail .
To print two negatives at once you must either use a glass nega- tive carrier , or modify other carriers by using a glass slide mount to hold the two negatives firmly so they can be focused together . The negatives should be sand- wiched emulsion sides inward . If the images will only work well the other way around , you must use a small lens aperture to keep both images sharp .
First negative
Second negative
Final print
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