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العمل على المطبوعات - ١ - المعالجة والطباعة .. كيفية التقاط وتطوير الصور بالأبيض والأسود
WORKING ON THE PRINT
Retouching is a skill that can be used both to correct faults and to introduce major changes and special effects . At its least noticeable and simplest , retouch- ing is simply a matter of ' spotting ' : using dyes on the tip of a fine paintbrush to clear up dust specks on a print . Most retouching , in fact , is confined to tidying up the image and correcting mistakes , although as a matter of principle it is better to avoid the faults in the first place by handling the film carefully at all stages , from exposure to processing .
The level of skill that you need depends partly on the medium . Prints are much easier to work on than film , and black - and - white is easier than colour . If you shoot in 35mm , detailed retouching is all but impossible , because of the size of the negative . The larger the form of the image , the better . If , however , there is something that can be done to the negative , this will later be much more convenient than retouching each individual print made from the same negative .
There are four possible retouching techniques and while it is only rarely that all need to be used together on the same image , they should be applied in the following order :
1. Chemical baths ( eg reducing or intensifying the negative , or bleaching areas of the print ) .
2. Dyes .
3. Knifing and any other physical attention .
4. Opaque pigment .
This order is important . For instance , if you add a dye over a part of the print that has already been knifed , it will run uncontrollably into the damaged area and seep under the surrounding emulsion .
In principle , plan the retouching beforehand , starting on broad areas and finishing with the finest details . With every technique , do a little at a time , building up the effect slowly . One of the most common mistakes in retouching is to overdo it .
EQUIPMENT AND MATERIALS
For retouching a print , work on a well - lit surface : an adjustable desk - lamp is ideal . For bleaching , have a dilute solution , cotton swabs , and plenty of water available nearby to halt the bleaching effect . Sets of transparent dyes in a range of off - blacks make it possible to mix one that matches the print image exactly . Use fine camel - hair brushes , a mixing palette and water for dilution . A scalpel or razor blade is for scraping away the top layer of the print emulsion , and opaque pigments in black and white can be used ( sparingly ) to block out small details .
If the retouching has been so extensive that it shows in the altered surface of the print , it may be worth copying the print onto a fresh negative and then re- printing from that .
How to Re - Touch Prints
Reducing print density :
1. Pre - soak the print in water for 10 minutes to soften the emulsion and paper - base .
2. Lay the print on a smooth surface , such as a sheet of glass , and swab off excess water .
3. With brushes or cotton swabs , apply the diluted bleach or reducing solution to the print . If you are in any doubt about how fast the solution will work , or whether it will cause any discolouration , test first on an unwanted print . In any case , use a very diluted solution so that you have more control . Work the solution over the print continuously so as to avoid hard and conspicuous edges to the reduced area .
4. Use a cotton swab and either plain water or hypo to halt the bleaching action when you judge the effect to be right .
Painting with Dyes
1. Pre - soak the print in water for 10 minutes . This enables the dye to penetrate more easily , and prevents hard edges to the dye washes .
2. On a sheet of glass , or other smooth working surface , swab off water droplets and allow the print to dry slightly for about 10 minutes .
3. With either rubber cement or self- adhesive masking film , mask off the areas that are to be untreated . Using a sharp scalpel , cut round the edges of the area to be dyed with just enough pressure to break the film but not enough to damage the print . Peel off the film from the areas that have been cut round . Mix a dilute solution of dye , making sure that it matches the hue of the print . Working from two dye bottles , one brownish - black and other bluish - black , you can prepare a precise match . Apply the dye in washes with a brush . Build up the density in a number of applications . If you make a mistake , or find that the added density is too great , place the entire print under running water for several minutes and begin again .
Re - Touching Equipment
Basic items are a can of compressed air ( 1 ) , and an airbrush ( 2 ) , with transparent masking film to cover areas not being re- touched ( 3 ) . Re - touching fluid ( 4 ) , gives a bite ' to the print surface . Bleach ( 5 ) and hypo crystals ( 6 ) are also needed , and rubber cement ( 7 ) can be used for complicated masking . Watercolour pigments ( 8 ) are used in the airbrush and a scalpel ( 9 ) for cutting and knifing .
Knifing to Remove Dark Spots
1. With the broad edge of a sharp scalpel blade , gently shave the blemish on the print's surface . Make short strokes , keeping your fingers steady and using your wrist for movement .
2. Stop before all the emulsion is removed , otherwise the roughened paper base will begin to show through .
3. For small spots , use the top of the blade , but remember that there is a greater risk with this method of cutting through to the paper base . Knifing should never be done before any wet re - touching ( such as bleaching or dye application ) as it physically damages the print and can result in dye bleeding away from its area of application .
WORKING ON THE PRINT
Retouching is a skill that can be used both to correct faults and to introduce major changes and special effects . At its least noticeable and simplest , retouch- ing is simply a matter of ' spotting ' : using dyes on the tip of a fine paintbrush to clear up dust specks on a print . Most retouching , in fact , is confined to tidying up the image and correcting mistakes , although as a matter of principle it is better to avoid the faults in the first place by handling the film carefully at all stages , from exposure to processing .
The level of skill that you need depends partly on the medium . Prints are much easier to work on than film , and black - and - white is easier than colour . If you shoot in 35mm , detailed retouching is all but impossible , because of the size of the negative . The larger the form of the image , the better . If , however , there is something that can be done to the negative , this will later be much more convenient than retouching each individual print made from the same negative .
There are four possible retouching techniques and while it is only rarely that all need to be used together on the same image , they should be applied in the following order :
1. Chemical baths ( eg reducing or intensifying the negative , or bleaching areas of the print ) .
2. Dyes .
3. Knifing and any other physical attention .
4. Opaque pigment .
This order is important . For instance , if you add a dye over a part of the print that has already been knifed , it will run uncontrollably into the damaged area and seep under the surrounding emulsion .
In principle , plan the retouching beforehand , starting on broad areas and finishing with the finest details . With every technique , do a little at a time , building up the effect slowly . One of the most common mistakes in retouching is to overdo it .
EQUIPMENT AND MATERIALS
For retouching a print , work on a well - lit surface : an adjustable desk - lamp is ideal . For bleaching , have a dilute solution , cotton swabs , and plenty of water available nearby to halt the bleaching effect . Sets of transparent dyes in a range of off - blacks make it possible to mix one that matches the print image exactly . Use fine camel - hair brushes , a mixing palette and water for dilution . A scalpel or razor blade is for scraping away the top layer of the print emulsion , and opaque pigments in black and white can be used ( sparingly ) to block out small details .
If the retouching has been so extensive that it shows in the altered surface of the print , it may be worth copying the print onto a fresh negative and then re- printing from that .
How to Re - Touch Prints
Reducing print density :
1. Pre - soak the print in water for 10 minutes to soften the emulsion and paper - base .
2. Lay the print on a smooth surface , such as a sheet of glass , and swab off excess water .
3. With brushes or cotton swabs , apply the diluted bleach or reducing solution to the print . If you are in any doubt about how fast the solution will work , or whether it will cause any discolouration , test first on an unwanted print . In any case , use a very diluted solution so that you have more control . Work the solution over the print continuously so as to avoid hard and conspicuous edges to the reduced area .
4. Use a cotton swab and either plain water or hypo to halt the bleaching action when you judge the effect to be right .
Painting with Dyes
1. Pre - soak the print in water for 10 minutes . This enables the dye to penetrate more easily , and prevents hard edges to the dye washes .
2. On a sheet of glass , or other smooth working surface , swab off water droplets and allow the print to dry slightly for about 10 minutes .
3. With either rubber cement or self- adhesive masking film , mask off the areas that are to be untreated . Using a sharp scalpel , cut round the edges of the area to be dyed with just enough pressure to break the film but not enough to damage the print . Peel off the film from the areas that have been cut round . Mix a dilute solution of dye , making sure that it matches the hue of the print . Working from two dye bottles , one brownish - black and other bluish - black , you can prepare a precise match . Apply the dye in washes with a brush . Build up the density in a number of applications . If you make a mistake , or find that the added density is too great , place the entire print under running water for several minutes and begin again .
Re - Touching Equipment
Basic items are a can of compressed air ( 1 ) , and an airbrush ( 2 ) , with transparent masking film to cover areas not being re- touched ( 3 ) . Re - touching fluid ( 4 ) , gives a bite ' to the print surface . Bleach ( 5 ) and hypo crystals ( 6 ) are also needed , and rubber cement ( 7 ) can be used for complicated masking . Watercolour pigments ( 8 ) are used in the airbrush and a scalpel ( 9 ) for cutting and knifing .
Knifing to Remove Dark Spots
1. With the broad edge of a sharp scalpel blade , gently shave the blemish on the print's surface . Make short strokes , keeping your fingers steady and using your wrist for movement .
2. Stop before all the emulsion is removed , otherwise the roughened paper base will begin to show through .
3. For small spots , use the top of the blade , but remember that there is a greater risk with this method of cutting through to the paper base . Knifing should never be done before any wet re - touching ( such as bleaching or dye application ) as it physically damages the print and can result in dye bleeding away from its area of application .
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