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كاميرات الأفلام الورقية كبيرة الحجم .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
Large format sheet film cameras
A large format camera , usually 4 × 5 ins , is quite simple in design . This kind of camera is used mostly for architectural and studio still - life work . It consists of a lens and bladed shutter mounted on a panel at one end of the bellows . At the other end there is a ground glass focusing screen .
Large format cameras have some par- ticular advantages . Pictures are exposed on separate sheets of film , which can be pro- cessed individually to suit subject and lighting conditions . You can use a wide range of films , from line and other black and white films to instant picture and color films . The large negatives produced by these cameras can be easily retouched ; they need less enlargement , and give finer image detail . You can also move the lens and film on large format cameras to control per- spective and depth of field , as explained overleaf . Because of the long bellows you can work very close - up to the subject with- out using extension tubes .
Large format cameras are slow to set up and use a tripod is essential . The image seen on the focusing screen is upside - down . Outdoors you must have a hood or a camera cloth over your head to be able to see the subject . Finally , there is delay between focusing the image and inserting and exposing the film , so that action pictures are almost impossible unless pre - planned .
Basic types of large format camera
There are two main types of large format cameras . The folding view camera , left , is still mostly made of wood . The monorail camera . below , uses a similar system but consists of metal units which are racked along a rail for focusing and camera movements
Baseboard camera
Bellows
Baseboard
Rails
Interchangeable lens
Monorail camera
Tilt and shift control
Lens and shutter on removeable panel
Bellows
Swing and lateral shift control
Focusing control
Monorail
Film holders
All large format cameras use sheet film , loaded in holders . Most take pictures 5 × 4 ins , although there are some 10 × 8 ins models . Other large format cameras are made , or can be adapted , for 2 × 3 ins and 12 x 9 cm size film . The usual film holder takes only two sheets , which must be loaded in the dark . You insert the holder into the back of the camera and , after one exposure , turn it the other way around . You can use a film pack back . This con- tains 16 sheets of ready loaded film which are moved into position one at a time by pulling a tab . You can also obtain backs for Polaroid instant picture films and rollfilms .
Sheet film holder
Film pack back
Polaroid back
Interchangeable bellows
You can detach , add to , or re- arrange the units of a monorail camera very easily . The normal bellows , for example , unclips at each end and can be replaced by bag bellows . This does not have the usual concertina folds . Con- sequently it allows you to position a wide - angle lens close to the film , but still enables you to shift the lens and make other camera movements . To work close - up you add extension bellows . These fit between the regular bellows and the lens panel and so increase the length of the normal bellows .
Extension bellows
Bag bellows
Inverting focusing hood
This hood overcomes the nuisance of an upside - down image , and at the same time shields the focusing screen from stray light . The hood clips on to the back of the camera and you look down through an eyepiece on to a large mirror which reflects the focusing screen image the right way up .
Large format sheet film cameras
A large format camera , usually 4 × 5 ins , is quite simple in design . This kind of camera is used mostly for architectural and studio still - life work . It consists of a lens and bladed shutter mounted on a panel at one end of the bellows . At the other end there is a ground glass focusing screen .
Large format cameras have some par- ticular advantages . Pictures are exposed on separate sheets of film , which can be pro- cessed individually to suit subject and lighting conditions . You can use a wide range of films , from line and other black and white films to instant picture and color films . The large negatives produced by these cameras can be easily retouched ; they need less enlargement , and give finer image detail . You can also move the lens and film on large format cameras to control per- spective and depth of field , as explained overleaf . Because of the long bellows you can work very close - up to the subject with- out using extension tubes .
Large format cameras are slow to set up and use a tripod is essential . The image seen on the focusing screen is upside - down . Outdoors you must have a hood or a camera cloth over your head to be able to see the subject . Finally , there is delay between focusing the image and inserting and exposing the film , so that action pictures are almost impossible unless pre - planned .
Basic types of large format camera
There are two main types of large format cameras . The folding view camera , left , is still mostly made of wood . The monorail camera . below , uses a similar system but consists of metal units which are racked along a rail for focusing and camera movements
Baseboard camera
Bellows
Baseboard
Rails
Interchangeable lens
Monorail camera
Tilt and shift control
Lens and shutter on removeable panel
Bellows
Swing and lateral shift control
Focusing control
Monorail
Film holders
All large format cameras use sheet film , loaded in holders . Most take pictures 5 × 4 ins , although there are some 10 × 8 ins models . Other large format cameras are made , or can be adapted , for 2 × 3 ins and 12 x 9 cm size film . The usual film holder takes only two sheets , which must be loaded in the dark . You insert the holder into the back of the camera and , after one exposure , turn it the other way around . You can use a film pack back . This con- tains 16 sheets of ready loaded film which are moved into position one at a time by pulling a tab . You can also obtain backs for Polaroid instant picture films and rollfilms .
Sheet film holder
Film pack back
Polaroid back
Interchangeable bellows
You can detach , add to , or re- arrange the units of a monorail camera very easily . The normal bellows , for example , unclips at each end and can be replaced by bag bellows . This does not have the usual concertina folds . Con- sequently it allows you to position a wide - angle lens close to the film , but still enables you to shift the lens and make other camera movements . To work close - up you add extension bellows . These fit between the regular bellows and the lens panel and so increase the length of the normal bellows .
Extension bellows
Bag bellows
Inverting focusing hood
This hood overcomes the nuisance of an upside - down image , and at the same time shields the focusing screen from stray light . The hood clips on to the back of the camera and you look down through an eyepiece on to a large mirror which reflects the focusing screen image the right way up .
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