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معدات التكبير والطباعة .. البدء .. كيفية التقاط وتطوير الصور بالأبيض والأسود
ENLARGER & PRINTING EQUIPMENT
Unlike colour , black - and - white photography is geared totally towards printing With the very minor exception of slides for projection ( Agfa make a reversal film , and Polaroid 35mm instant films give a positive image ) , black - and - white films are only a preliminary stage . The end - product that justifies the effort is an enlarged print . After the camera equipment , the most important item is an enlarger .
Fortunately , a black - and - white enlarger is neither as complex nor as expens- ive as an enlarger designed for colour printing . There is no need for colour filters ( either a red safety filter fitted to some models for swinging in front of the lens , and the filter set used with variable - contrast paper ) , and the colour balance of the lamp is not so important .
Nevertheless , a good enlarger is a significant investment , and ought to be chosen carefully . First , the size : enlargers are available for all film formats up to sheet film , and the larger sizes will accept all smaller formats . If you think that you might upgrade from 35mm to rollfilm at some point , it is worth getting a medium - format enlarger to begin with . Two focal lengths of enlarger lens will then allow you to print both sizes of negative . As with the camera , what ulti- mately decides the image quality is the quality of the lens . This is no place to skimp : the enlarger lens should be at least as good as your camera lenses , otherwise you will have wasted their value . For normal enlargements , use a lens that has the same focal length as the standard lens for the format . 50mm or 60mm are the usual choice for 35mm , 80mm or 90mm for rollfilm .
The head of the enlarger contains the light source , and there are two alterna- tive systems : condensers or diffused lamps . In the first , condenser lenses , usu- ally different for each focal length of enlarging lens , focus the light from a small lamp on the negative ; in the second , the light is from a large area , and is unfocused and diffuse . Condensers give a slightly sharper and more contrasty image on the print , although they also make the film grain and any blemishes appear more prominently .
An easel is needed to hold the paper in place and give a neat border to the image . The normal design has adjustable masks - strips of metal or plastic - that can be altered for different proportions and sizes . A focusing magnifier focuses on the grain of the negative , and is useful for getting the sharpest possible images .
Contact prints , which are normally made before finished prints as a means of selecting photographs , are made by pressing the negative strips flat against a sheet of printing paper . A sheet of plain glass will do , but a purpose - built contact printing frame is easier to use .
Other equipment includes a red safelight , anti - static brush for cleaning nega- tives , dodging tools , and processing trays with tongs ( if you use different sizes of paper , different sets of trays make more economical use of the processing solutions ) .
ABOVE AND ABOVE RIGHT There are two basic choices when deciding upon an enlarger head for black - and- white printing that features a diffuser lamp , which spreads the light over a large area and is more forgiving , or one which has a condenser lamp , where the light is focused from the small lamp on the negative .
ABOVE Film carrier types include an adjustable mask for different film formats ( 1 ) , a glass carrier to hold thin film flat ( 2 ) , and a hinged plate ( 3 ) .
BELOW Black - and - white enlargers tend to be more simple than their colour counterparts , offering a basic means of exposing an image on a negative to light - sensitive paper .
Maintenance Checklist
Check for the following faults :
1. Dirt on the lens . Causes flare and vague dark spots when stopped down .
2. Dirt on condensers or filters . Causes soft - edged dark spots on print at small apertures .
3. Wrong condensers . Make sure they match the focal length of the enlarging lens .
4. Unsteady baseboard . Causes double or blurred image .
5. Torn bellows or gaps in enlarger head . Can cause fogging of print .
6. Condensers badly adjusted . Causes darkenening towards edges of projected image .
7. Wrong enlarging lens . If lens does not cover negative , illumination and image quality fall off toward the edges of the projected image .
8. Focus gears slip . Causes soft focus . Tighten locking screws or relubricate .
ENLARGER & PRINTING EQUIPMENT
Unlike colour , black - and - white photography is geared totally towards printing With the very minor exception of slides for projection ( Agfa make a reversal film , and Polaroid 35mm instant films give a positive image ) , black - and - white films are only a preliminary stage . The end - product that justifies the effort is an enlarged print . After the camera equipment , the most important item is an enlarger .
Fortunately , a black - and - white enlarger is neither as complex nor as expens- ive as an enlarger designed for colour printing . There is no need for colour filters ( either a red safety filter fitted to some models for swinging in front of the lens , and the filter set used with variable - contrast paper ) , and the colour balance of the lamp is not so important .
Nevertheless , a good enlarger is a significant investment , and ought to be chosen carefully . First , the size : enlargers are available for all film formats up to sheet film , and the larger sizes will accept all smaller formats . If you think that you might upgrade from 35mm to rollfilm at some point , it is worth getting a medium - format enlarger to begin with . Two focal lengths of enlarger lens will then allow you to print both sizes of negative . As with the camera , what ulti- mately decides the image quality is the quality of the lens . This is no place to skimp : the enlarger lens should be at least as good as your camera lenses , otherwise you will have wasted their value . For normal enlargements , use a lens that has the same focal length as the standard lens for the format . 50mm or 60mm are the usual choice for 35mm , 80mm or 90mm for rollfilm .
The head of the enlarger contains the light source , and there are two alterna- tive systems : condensers or diffused lamps . In the first , condenser lenses , usu- ally different for each focal length of enlarging lens , focus the light from a small lamp on the negative ; in the second , the light is from a large area , and is unfocused and diffuse . Condensers give a slightly sharper and more contrasty image on the print , although they also make the film grain and any blemishes appear more prominently .
An easel is needed to hold the paper in place and give a neat border to the image . The normal design has adjustable masks - strips of metal or plastic - that can be altered for different proportions and sizes . A focusing magnifier focuses on the grain of the negative , and is useful for getting the sharpest possible images .
Contact prints , which are normally made before finished prints as a means of selecting photographs , are made by pressing the negative strips flat against a sheet of printing paper . A sheet of plain glass will do , but a purpose - built contact printing frame is easier to use .
Other equipment includes a red safelight , anti - static brush for cleaning nega- tives , dodging tools , and processing trays with tongs ( if you use different sizes of paper , different sets of trays make more economical use of the processing solutions ) .
ABOVE AND ABOVE RIGHT There are two basic choices when deciding upon an enlarger head for black - and- white printing that features a diffuser lamp , which spreads the light over a large area and is more forgiving , or one which has a condenser lamp , where the light is focused from the small lamp on the negative .
ABOVE Film carrier types include an adjustable mask for different film formats ( 1 ) , a glass carrier to hold thin film flat ( 2 ) , and a hinged plate ( 3 ) .
BELOW Black - and - white enlargers tend to be more simple than their colour counterparts , offering a basic means of exposing an image on a negative to light - sensitive paper .
Maintenance Checklist
Check for the following faults :
1. Dirt on the lens . Causes flare and vague dark spots when stopped down .
2. Dirt on condensers or filters . Causes soft - edged dark spots on print at small apertures .
3. Wrong condensers . Make sure they match the focal length of the enlarging lens .
4. Unsteady baseboard . Causes double or blurred image .
5. Torn bellows or gaps in enlarger head . Can cause fogging of print .
6. Condensers badly adjusted . Causes darkenening towards edges of projected image .
7. Wrong enlarging lens . If lens does not cover negative , illumination and image quality fall off toward the edges of the projected image .
8. Focus gears slip . Causes soft focus . Tighten locking screws or relubricate .
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