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تقييم السلبيات .. المعالجة والطباعة بالأبيض والأسود .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
Assessing negatives
Wait until the film is completely dry before assessing your results in detail . The film can be seen best if it is held a short distance away from an evenly lit sheet of white paper ; use a magnifying glass if necessary . If you are not used to reading negatives , the images will seem almost unrecognizable at first , with subject highlights dark and shadows light . However , you can now check three important aspects of the negative : density , sharpness , and marks .
Density and sharpness
The density of the negative is affected by exposure and development and is measured by how light ( or dark ) , contrasty ( or flat ) it appears . Check the density by looking to see if detail has recorded in important high- lights and shadows in the picture ( ignore plain white or black backgrounds ) . How strong is the difference ( contrast ) between the highlights and shadows ? Negatives which look very bright or contrasty are often too harsh to print . Ideally , a black and white negative should have rather low con- trast with plenty of detail to print well . Use a magnifier to check if the image is sharp over- all or at least in those areas which you wanted to record clearly .
Marks
Look for scratches , uneven processing marks , bits of dust or finger marks on the film , as these will all show up on the print .
Assessing the final negative
Highlight
On the print , this will be the bright- est area . It should be dark on the negative , but still show detail .
Sharpness
Assess sharpness by checking fine detail areas such as a necklace , eyes . or teeth .
Shadow
The man's hair will be the darkest main shadow area on the print . It should con- tain detail .
Tones
There should be a wide range of gray tones to give detail and " roundness " to the image .
Analyzing spoilt negatives
Serious marks on the negative , or even complete absence of image , could have been caused during either exposure or processing . The letters and figures in the re- bates ( margins ) of the film will help you discover when the fault arose If they are present then the fault occured during exposure . since a mistake during processing would affect all of the film .
Exposure errors
If your film is clear , with no nega- tives at all , but the characters in the rebates are present , then the film was unexposed . This happens if the film is not wound on prop- erly in the camera . A black film ( with normal rebates ) results when the film is rewound in the camera with the shutter open .
Processing errors
If both rebates and film are clear . then the film was not developed . You may have used fixer and developer in the wrong order . A totally black film was probably " fogged " ( accidentally exposed ) in the darkroom . Other , typical pro- cessing faults are shown right .
Insufficient developer
An uneven band throughout the film , shown above , is caused by having insufficient developer in the tank . You can avoid this by measuring the capacity of your tank beforehand using water and a graduate ( measuring jug ) .
Film contact
The blemish above occurs when film touches itself in the develop- ing tank . The resulting mark is creamy gray or ( if the film has separated during fixing ) com- pletely transparent . You can detect where the film might be in con- tact with itself by running your fingers around the outside of the reel ( as shown on p . 69 ) .
Water marks
The negative above shows water marks which are usually due to uneven drying or splashes of water on the film while it was drying . Always remember that film is extremely sensitive both before and after processing .
Underexposure
Both underexposure and under- development give thin negatives . but underexposure also creates empty shadows . Detail in the areas of highlight is usually excel- lent and of normal contrast . Underexposure could result from setting the wrong ( too fast ) ASA film speed on your camera or light meter , measuring the light from the highlight areas only , or simply setting too short a shutter speed or too small an aperture .
Little can be done to improve a seriously underexposed negative : keep to a dark ( overexposed ) print the picture may be able to be read from mid - tones and high- light areas alone . A typical print from an underexposed negative has solid black shadows or , if given a shorter exposure , it will have flat gray areas .
A print on normal grade paper from an underexposed negative .
Overexposure
A dark , dense negative , which has less contrast than that created by overdevelopment , is produced by overexposure . Shadow detail is reasonable but highlight areas are dense and flat with little detail . The usual causes of overexposure are : setting the wrong ( too slow ) ASA speed on your camera or light meter , taking a light reading only from the darkest areas of the subject , or having too slow a shut- ter speed or too wide an aperture .
Often you can improve the negative by using a reducing solution ( see pp . 124-5 ) , but this will make the grain pattern more visible . Detail in the highlight areas on the print can be im- proved by giving a long printing exposure on a hard grade paper ( see pp . 82-3 ) .
A print on normal grade paper from an overexposed negative .
Underdevelopment
Underdevelopment produces a negative which is weak , or " thin " . with lower than normal contrast . Shadow detail is barely present and highlights are gray rather than black . This happens if the develop- er was partly exhausted , over- diluted , or too low in temperature ; or when the development time was too short for the type of film .
It is possible to remedy mild underdevelopment by intensifica- tion during printing ( see pp . 124-5 ) . Otherwise a print on normal grade paper looks flat and gray . Better results can be achiev- ed by printing on extra hard paper ( see pp . 82-3 ) .
If you want to take a picture of a subject which is harshly lit , slight overexposure followed by underdevelopment may give you a normal contrast negative .
A print on normal grade paper from an underdeveloped negative .
Overdevelopment
A negative which looks dense , or " thick " , and contrasty is over- developed . You will find that shadow detail is bright and strong while tones merge in subject highlight areas . The causes and the effects are the exact opposites to underdevelopment . Over- development is caused by the developer being too warm , too concentrated , or when the develop- ment time is too long for the film .
Some reducers ( see pp . 124-5 ) will remedy overdevelopment . by chemically lightening the nega- tive . Otherwise a print on normal grade paper is bleached and con- trasty . Printing on extra soft paper will improve this ( see pp . 82-3 ) . Slight overdevelopment can compensate when the subject and lighting are flat and gray .
A print on normal grade paper from an overdeveloped negative .
Assessing negatives
Wait until the film is completely dry before assessing your results in detail . The film can be seen best if it is held a short distance away from an evenly lit sheet of white paper ; use a magnifying glass if necessary . If you are not used to reading negatives , the images will seem almost unrecognizable at first , with subject highlights dark and shadows light . However , you can now check three important aspects of the negative : density , sharpness , and marks .
Density and sharpness
The density of the negative is affected by exposure and development and is measured by how light ( or dark ) , contrasty ( or flat ) it appears . Check the density by looking to see if detail has recorded in important high- lights and shadows in the picture ( ignore plain white or black backgrounds ) . How strong is the difference ( contrast ) between the highlights and shadows ? Negatives which look very bright or contrasty are often too harsh to print . Ideally , a black and white negative should have rather low con- trast with plenty of detail to print well . Use a magnifier to check if the image is sharp over- all or at least in those areas which you wanted to record clearly .
Marks
Look for scratches , uneven processing marks , bits of dust or finger marks on the film , as these will all show up on the print .
Assessing the final negative
Highlight
On the print , this will be the bright- est area . It should be dark on the negative , but still show detail .
Sharpness
Assess sharpness by checking fine detail areas such as a necklace , eyes . or teeth .
Shadow
The man's hair will be the darkest main shadow area on the print . It should con- tain detail .
Tones
There should be a wide range of gray tones to give detail and " roundness " to the image .
Analyzing spoilt negatives
Serious marks on the negative , or even complete absence of image , could have been caused during either exposure or processing . The letters and figures in the re- bates ( margins ) of the film will help you discover when the fault arose If they are present then the fault occured during exposure . since a mistake during processing would affect all of the film .
Exposure errors
If your film is clear , with no nega- tives at all , but the characters in the rebates are present , then the film was unexposed . This happens if the film is not wound on prop- erly in the camera . A black film ( with normal rebates ) results when the film is rewound in the camera with the shutter open .
Processing errors
If both rebates and film are clear . then the film was not developed . You may have used fixer and developer in the wrong order . A totally black film was probably " fogged " ( accidentally exposed ) in the darkroom . Other , typical pro- cessing faults are shown right .
Insufficient developer
An uneven band throughout the film , shown above , is caused by having insufficient developer in the tank . You can avoid this by measuring the capacity of your tank beforehand using water and a graduate ( measuring jug ) .
Film contact
The blemish above occurs when film touches itself in the develop- ing tank . The resulting mark is creamy gray or ( if the film has separated during fixing ) com- pletely transparent . You can detect where the film might be in con- tact with itself by running your fingers around the outside of the reel ( as shown on p . 69 ) .
Water marks
The negative above shows water marks which are usually due to uneven drying or splashes of water on the film while it was drying . Always remember that film is extremely sensitive both before and after processing .
Underexposure
Both underexposure and under- development give thin negatives . but underexposure also creates empty shadows . Detail in the areas of highlight is usually excel- lent and of normal contrast . Underexposure could result from setting the wrong ( too fast ) ASA film speed on your camera or light meter , measuring the light from the highlight areas only , or simply setting too short a shutter speed or too small an aperture .
Little can be done to improve a seriously underexposed negative : keep to a dark ( overexposed ) print the picture may be able to be read from mid - tones and high- light areas alone . A typical print from an underexposed negative has solid black shadows or , if given a shorter exposure , it will have flat gray areas .
A print on normal grade paper from an underexposed negative .
Overexposure
A dark , dense negative , which has less contrast than that created by overdevelopment , is produced by overexposure . Shadow detail is reasonable but highlight areas are dense and flat with little detail . The usual causes of overexposure are : setting the wrong ( too slow ) ASA speed on your camera or light meter , taking a light reading only from the darkest areas of the subject , or having too slow a shut- ter speed or too wide an aperture .
Often you can improve the negative by using a reducing solution ( see pp . 124-5 ) , but this will make the grain pattern more visible . Detail in the highlight areas on the print can be im- proved by giving a long printing exposure on a hard grade paper ( see pp . 82-3 ) .
A print on normal grade paper from an overexposed negative .
Underdevelopment
Underdevelopment produces a negative which is weak , or " thin " . with lower than normal contrast . Shadow detail is barely present and highlights are gray rather than black . This happens if the develop- er was partly exhausted , over- diluted , or too low in temperature ; or when the development time was too short for the type of film .
It is possible to remedy mild underdevelopment by intensifica- tion during printing ( see pp . 124-5 ) . Otherwise a print on normal grade paper looks flat and gray . Better results can be achiev- ed by printing on extra hard paper ( see pp . 82-3 ) .
If you want to take a picture of a subject which is harshly lit , slight overexposure followed by underdevelopment may give you a normal contrast negative .
A print on normal grade paper from an underdeveloped negative .
Overdevelopment
A negative which looks dense , or " thick " , and contrasty is over- developed . You will find that shadow detail is bright and strong while tones merge in subject highlight areas . The causes and the effects are the exact opposites to underdevelopment . Over- development is caused by the developer being too warm , too concentrated , or when the develop- ment time is too long for the film .
Some reducers ( see pp . 124-5 ) will remedy overdevelopment . by chemically lightening the nega- tive . Otherwise a print on normal grade paper is bleached and con- trasty . Printing on extra soft paper will improve this ( see pp . 82-3 ) . Slight overdevelopment can compensate when the subject and lighting are flat and gray .
A print on normal grade paper from an overdeveloped negative .
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