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تطوير السلبية ..
كيفية التعامل مع ورقة فيلم وتطويرها - ١ -
HOW TO HANDLE AND DEVELOP SHEET FILM
If you have a camera that uses sheet film , much of what we say here may not be new to you , but we strongly urge you to read it carefully anyhow . The procedures and precautions we will discuss in this part of the Assignment have been worked out very carefully by experts , and even if you have been processing your own sheet film , you will undoubtedly pick up a lot of additional useful information . For the newcomer to this field , of course , very careful attention to all details is essential to success .
Sheet film is quite a bit thicker and heavier than ordinary roll film so it stays relatively flat even in the larger sizes . It can therefore be successfully used in an individual film holder in a camera and in the film processing solutions . It will not curl , but will remain quite flat under all conditions of normal use .
Fig . 13 Typical cut film code notches . As shown , when the notch is in the upper right corner , the emulsion side of the film is facing you .
Once a sheet of film is outside of the box , it is indistinguishable from all other types of sheet film with but few exceptions so that its identity becomes lost . The manufacturer has , therefore , put a series of identification notches on one of the short edges to identify the type of film and also which of the two sides is the emulsion side . If you hold a sheet of film in such a way that the coding notches are on the right side of the top edge , the emulsion side will be facing you .
Another important problem you will face in the handling of sheet film is how to tell whether the holder contains film and if so whether the film is exposed or unexposed . The only safe way to prevent a mixup and keep from making two exposures on a single sheet of film or shooting with an empty film holder is to adopt the standard procedure to be outlined here . All commercial photographers follow this procedure so that it has become standard in the industry .
If you look at a film holder slide , you will see that the top metal binding strip on each slide is black on one side and either aluminum color or white on the other side . The white side also usually has a series of raised dots so that you can tell which is the white side in total darkness . At the top of the film holder
between the two slides , you will see two small metal hooks which can be turned to hold these slides in position so that they cannot be pulled out accidentally .
When the holder is empty , these hooks should be turned in such a way as to permit the slides to be pulled out . Therefore , when you pick up a slide holder and the hooks are in the open position , you know the holder is empty . When you load a holder , always insert the slide so that the white side is out . This means that the film has not been exposed as yet . When you make the exposure and return the slide in the holder , be sure to insert it so side is out . This is a sign that the film has been exposed . Of course , in either case , whether the film is exposed or unexposed , the hooks must be turned so as to lock the slides in position . This is not only a safety precaution , but a signal to everybody who handles the holder that it is loaded .
LOADING FILM HOLDERS . Before loading a set of sheet film holders , make sure that the darkroom bench is absolutely clean and dust free . Make certain you have enough working space and carefully note the location of everything you work with so that you can load the holders in complete darkness . Most films are panchromatic with highly sensitive emulsions and must be loaded in complete . darkness . You must , therefore , practice loading and unloading film holders until you have become expert enough to work in complete darkness . Practice sessions can , of course , be undertaken with a few sheets of spoiled or excess film in ordinary white light .
The first step is to prepare the holders for loading . This can be done in white light . First remove the dark slides and stack them upright against the wall with the white side out . If the loading table is covered with ribbed rubber matting , there is no likelihood that the slides will slide forward . Stack the empty film holder in front of its two dark slides . Then stack the two slides of the next holder in front of the first holder , and continue this . operation until you have prepared as many holders as you expect to load at one time . ( See Figure 14. )
Fig . 14 Preparations for loading cut film holders . Study the location of holders , dark slides , and film so you can find them easily and quickly in the dark .
You are now ready to load the film holders . A box of sheet film generally contains 25 sheets . A sheet of soft black paper is placed between films to protect their delicate surfaces during shipment and handling , and the package of film and interleaved paper is wrapped in black paper and then enclosed in a moisture proof bag of aluminum foil . This package is then enclosed in a box with three covers
instead of the usual two , so that the box acts as a labyrinth to prevent the entrance of stray , white light . The top cover is prevented from coming off accidentally by being sealed at both ends . When you are ready to load , you can slit the seals in white light , but be very careful not to remove the top cover until you have turned off all light in the darkroom and you are in total darkness . Now remove the covers and take the stack of films out of its protective wrappings . You will find it much easier to handle the film in the loading process if you place the unwrapped film emulsion side down across one of the empty box sections . If the emulsion faces down , there should be no danger of your getting fingerprints on it when you pick up the individual sheets of film for loading ..
Now carefully remove and discard the black interleaving sheet on top of the stack of film . Pick up this paper by a corner , carefully , and avoid applying pressure to the film below it . Lift the film by the notched corner with one or two fingers on the base side with your thumb touching only a narrow edge at the notches . Lift the film and turn it emulsion side up .
Pick up the first holder to be loaded . You may perform the loading operation with the holder in your hand or placed flat on the table , whichever seems most convenient for you Generally speaking , smaller film holders may be loaded while held the hand while the larger holders are much more conveniently loaded when they are placed flat on the table . In either case the bottom or flap end of the holder should point to the right . Hold the flap open with your left index finger and insert the sheet of film into the retaining channel nearest you . Now guide the other edge of the film into the other retaining channel with your left thumb . When this done , square up the film with the holder and slide it all the way in ( Figure 15 ) . Make sure that the film is actually inside both retaining guides and not , in fact , resting on top of one of them by lifting the end carefully to see if one side comes free . Also make certain that the top edge of the film has slipped underneath the retaining guide at the top of the holder by inserting a fingernail gently in the top film channel while pushing on the opposite end of the film . ( See Figure 16. )
Fig . 15 Open the bottom flap of the holder , and slowly slide film into the retaining channels . If you practiced this in the light , it will be easier in the dark .
Fig . 16 If the film is not pushed under the top film channel , the bottom flap will not close and the dark slide cannot be properly inserted .
Now close the bottom flap of the holder and note carefully whether the flap closes easily or not . If the film prevents the flap from closing , it has not been inserted all the way into the top channel . With the flap properly closed , replace the dark slide , bright side out . ( Figure 17. ) If the slide seems to meet resistance near the bottom of its travel , check to make sure that the film is properly inserted . If the film is not in one of its side channels , it may get in the way of slide , so this is an indication of faulty loading . When the slide is properly inserted , turn the retaining hook to keep it in place ( Figure 18 ) . The retaining hook is generally a screw so that it may be turned in or out until it fits the slide properly . If you have the habit of alway : the scre in one direction , you may turn it in too far or out too far , so check this point carefully or you may find that the slide retaining hook has turned out so far as to fall out and become lost .
Fig . 17 As you insert the dark slide , feel for the raised dots as a double check that the bright side is out .
Proceed in the same manner to load the other side of the holder . Stack the loaded holder against the wall and then continue with the others until they are all loaded .
UNLOADING FILM HOLDERS . To unload a film holder , simply reverse the loading procedure . However , it usually is not necessary to withdraw the slides entirely . Simply pull them out about half their length , then open the flap at the bottom of the holder , and pull out the film itself . The exposed films may then be put into a box for subsequent processing ( be sure to interleave each . sheet of film with a sheet of black paper ) or you may load them into the film processing hangers for immediate processing . In either case , close the film holders promptly so as to prevent dust from getting into them , but be sure to keep the retaining hooks in their open positions .
Fig . 18 As a final step , turn retaining hook so that it locks the dark slide into the holder .
PRECAUTIONS WHEN LOADING AND UNLOADING HOLDERS . Always handle sheet film carefully - for that matter , this precaution applies equally to all film whether sheet or roll . Avoid contact with the emulsion surface or you may find that you have spoiled an important negative with a set of fingerprints . This is particularly important in the summer when your hands are likely to be moist and oily . In winter when the relative humidity is very low , make an extra effort to handle films slowly and deliberately to prevent the building up of static charges of electricity which may develop into streaks or fine lines . This is particularly important when separating the film from the interleaving paper .
When removing the interleaving paper from a stack of film , be careful not to press down sharply or pinch the film below between your fingers . Such pressure may leave developing marks .
تطوير السلبية ..
كيفية التعامل مع ورقة فيلم وتطويرها - ١ -
HOW TO HANDLE AND DEVELOP SHEET FILM
If you have a camera that uses sheet film , much of what we say here may not be new to you , but we strongly urge you to read it carefully anyhow . The procedures and precautions we will discuss in this part of the Assignment have been worked out very carefully by experts , and even if you have been processing your own sheet film , you will undoubtedly pick up a lot of additional useful information . For the newcomer to this field , of course , very careful attention to all details is essential to success .
Sheet film is quite a bit thicker and heavier than ordinary roll film so it stays relatively flat even in the larger sizes . It can therefore be successfully used in an individual film holder in a camera and in the film processing solutions . It will not curl , but will remain quite flat under all conditions of normal use .
Fig . 13 Typical cut film code notches . As shown , when the notch is in the upper right corner , the emulsion side of the film is facing you .
Once a sheet of film is outside of the box , it is indistinguishable from all other types of sheet film with but few exceptions so that its identity becomes lost . The manufacturer has , therefore , put a series of identification notches on one of the short edges to identify the type of film and also which of the two sides is the emulsion side . If you hold a sheet of film in such a way that the coding notches are on the right side of the top edge , the emulsion side will be facing you .
Another important problem you will face in the handling of sheet film is how to tell whether the holder contains film and if so whether the film is exposed or unexposed . The only safe way to prevent a mixup and keep from making two exposures on a single sheet of film or shooting with an empty film holder is to adopt the standard procedure to be outlined here . All commercial photographers follow this procedure so that it has become standard in the industry .
If you look at a film holder slide , you will see that the top metal binding strip on each slide is black on one side and either aluminum color or white on the other side . The white side also usually has a series of raised dots so that you can tell which is the white side in total darkness . At the top of the film holder
between the two slides , you will see two small metal hooks which can be turned to hold these slides in position so that they cannot be pulled out accidentally .
When the holder is empty , these hooks should be turned in such a way as to permit the slides to be pulled out . Therefore , when you pick up a slide holder and the hooks are in the open position , you know the holder is empty . When you load a holder , always insert the slide so that the white side is out . This means that the film has not been exposed as yet . When you make the exposure and return the slide in the holder , be sure to insert it so side is out . This is a sign that the film has been exposed . Of course , in either case , whether the film is exposed or unexposed , the hooks must be turned so as to lock the slides in position . This is not only a safety precaution , but a signal to everybody who handles the holder that it is loaded .
LOADING FILM HOLDERS . Before loading a set of sheet film holders , make sure that the darkroom bench is absolutely clean and dust free . Make certain you have enough working space and carefully note the location of everything you work with so that you can load the holders in complete darkness . Most films are panchromatic with highly sensitive emulsions and must be loaded in complete . darkness . You must , therefore , practice loading and unloading film holders until you have become expert enough to work in complete darkness . Practice sessions can , of course , be undertaken with a few sheets of spoiled or excess film in ordinary white light .
The first step is to prepare the holders for loading . This can be done in white light . First remove the dark slides and stack them upright against the wall with the white side out . If the loading table is covered with ribbed rubber matting , there is no likelihood that the slides will slide forward . Stack the empty film holder in front of its two dark slides . Then stack the two slides of the next holder in front of the first holder , and continue this . operation until you have prepared as many holders as you expect to load at one time . ( See Figure 14. )
Fig . 14 Preparations for loading cut film holders . Study the location of holders , dark slides , and film so you can find them easily and quickly in the dark .
You are now ready to load the film holders . A box of sheet film generally contains 25 sheets . A sheet of soft black paper is placed between films to protect their delicate surfaces during shipment and handling , and the package of film and interleaved paper is wrapped in black paper and then enclosed in a moisture proof bag of aluminum foil . This package is then enclosed in a box with three covers
instead of the usual two , so that the box acts as a labyrinth to prevent the entrance of stray , white light . The top cover is prevented from coming off accidentally by being sealed at both ends . When you are ready to load , you can slit the seals in white light , but be very careful not to remove the top cover until you have turned off all light in the darkroom and you are in total darkness . Now remove the covers and take the stack of films out of its protective wrappings . You will find it much easier to handle the film in the loading process if you place the unwrapped film emulsion side down across one of the empty box sections . If the emulsion faces down , there should be no danger of your getting fingerprints on it when you pick up the individual sheets of film for loading ..
Now carefully remove and discard the black interleaving sheet on top of the stack of film . Pick up this paper by a corner , carefully , and avoid applying pressure to the film below it . Lift the film by the notched corner with one or two fingers on the base side with your thumb touching only a narrow edge at the notches . Lift the film and turn it emulsion side up .
Pick up the first holder to be loaded . You may perform the loading operation with the holder in your hand or placed flat on the table , whichever seems most convenient for you Generally speaking , smaller film holders may be loaded while held the hand while the larger holders are much more conveniently loaded when they are placed flat on the table . In either case the bottom or flap end of the holder should point to the right . Hold the flap open with your left index finger and insert the sheet of film into the retaining channel nearest you . Now guide the other edge of the film into the other retaining channel with your left thumb . When this done , square up the film with the holder and slide it all the way in ( Figure 15 ) . Make sure that the film is actually inside both retaining guides and not , in fact , resting on top of one of them by lifting the end carefully to see if one side comes free . Also make certain that the top edge of the film has slipped underneath the retaining guide at the top of the holder by inserting a fingernail gently in the top film channel while pushing on the opposite end of the film . ( See Figure 16. )
Fig . 15 Open the bottom flap of the holder , and slowly slide film into the retaining channels . If you practiced this in the light , it will be easier in the dark .
Fig . 16 If the film is not pushed under the top film channel , the bottom flap will not close and the dark slide cannot be properly inserted .
Now close the bottom flap of the holder and note carefully whether the flap closes easily or not . If the film prevents the flap from closing , it has not been inserted all the way into the top channel . With the flap properly closed , replace the dark slide , bright side out . ( Figure 17. ) If the slide seems to meet resistance near the bottom of its travel , check to make sure that the film is properly inserted . If the film is not in one of its side channels , it may get in the way of slide , so this is an indication of faulty loading . When the slide is properly inserted , turn the retaining hook to keep it in place ( Figure 18 ) . The retaining hook is generally a screw so that it may be turned in or out until it fits the slide properly . If you have the habit of alway : the scre in one direction , you may turn it in too far or out too far , so check this point carefully or you may find that the slide retaining hook has turned out so far as to fall out and become lost .
Fig . 17 As you insert the dark slide , feel for the raised dots as a double check that the bright side is out .
Proceed in the same manner to load the other side of the holder . Stack the loaded holder against the wall and then continue with the others until they are all loaded .
UNLOADING FILM HOLDERS . To unload a film holder , simply reverse the loading procedure . However , it usually is not necessary to withdraw the slides entirely . Simply pull them out about half their length , then open the flap at the bottom of the holder , and pull out the film itself . The exposed films may then be put into a box for subsequent processing ( be sure to interleave each . sheet of film with a sheet of black paper ) or you may load them into the film processing hangers for immediate processing . In either case , close the film holders promptly so as to prevent dust from getting into them , but be sure to keep the retaining hooks in their open positions .
Fig . 18 As a final step , turn retaining hook so that it locks the dark slide into the holder .
PRECAUTIONS WHEN LOADING AND UNLOADING HOLDERS . Always handle sheet film carefully - for that matter , this precaution applies equally to all film whether sheet or roll . Avoid contact with the emulsion surface or you may find that you have spoiled an important negative with a set of fingerprints . This is particularly important in the summer when your hands are likely to be moist and oily . In winter when the relative humidity is very low , make an extra effort to handle films slowly and deliberately to prevent the building up of static charges of electricity which may develop into streaks or fine lines . This is particularly important when separating the film from the interleaving paper .
When removing the interleaving paper from a stack of film , be careful not to press down sharply or pinch the film below between your fingers . Such pressure may leave developing marks .
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