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كاميرات الصور الفورية .. المرشد خطوة بخطوة للتصوير الفوتوغرافي
Instant picture cameras
As the name implies , instant picture cameras use special film which self - develops a few seconds or minutes after exposure . There are two types of material in common use- material you have to peel - apart , and integral processing material .
With a camera designed for peel - apart material , such as shown right , you expose the picture on a piece of light - sensitive paper or film . You then pull a tab which brings the film into contact with a receiving paper and pulls the two sheets from the camera through a pair of spring - loaded rollers These rollers spread chemicals between the two surfaces . After an appropriate number of seconds the time varies according to the temperature - you peel the sheets apart . A positive , right - way - round image is printed on the receiving paper . You then either discard the negative or , if you have used a black and white film designed for printing , wash the negative and retain it . Polaroid peel - apart film packs , for black and white and . color , also fit specially designed direct viewfinder cameras , and attachments for 120 rollfilm single lens reflex or 5 × 4 ins sheet film cameras .
Integral - processing instant picture ma- terials are made by both Polaroid and Kodak . The two systems are similar , but incompatible . In both systems one multi- layer sheet is used both for the exposure and the final print . This is ejected from the camera immediately after exposure as a creamy looking blank print , on which a color image gradually appears .
Peel - apart instant picture film
Peel - apart instant film is most widely used on simple viewfinder cameras , such as shown above , right . Peel- apart film backs , above left , are also made to fit rollfilm single lens reflex cameras .
Cameras for integral processing
Polaroid SX - 70 series
Viewfinder
Focus control
Shutter release
Exposure control
Lens
Kodak EK series
Viewfinder
Shutter release
Lens
Polaroid SX - 70 system
Polaroid's integral - processing instant picture material forms a finished color photograph on the same surface that received the image . The image is reflected by a mirror inside the camera so that it is not reversed left - to - right on the final print .
The SX - 70 is a special type of single lens reflex . During focusing a face - down hinged mirror covers the film pack . Light is reflected from a mirror fixed to the rear of the camera so that the image is seen and focused on the back of the face - down mirror , as shown right . When you take a picture the mirror rises , seals off the eye - piece , and reflects the image on to the light - sensitive material .
Motorized rollers then eject the card , spreading re - agent chemical and light - proof white pigment between the processing lower layers and the top receiving layers . Gradually yellow , magenta , and cyan dyes released from below rise and permeate the white surface to form a visible color picture .
Kodak EK system
In the Kodak instant picture system , right , one side of the multi - layer coated plastic sheet is exposed to the image , while the finished picture forms on the oppo- site side . So to form the final image the correct way around , either the exposing surface must face the lens directly , or the image must be reflected twice before reaching it .
Light from the lens is reflected twice in the camera by fixed mirrors on to the sensitive material . You compose the picture and aim the camera by means of a separate , direct vision viewfinder .
After exposure the eighteen- layered material is ejected through rollers which spread reagent within the film . Yellow , magenta , and cyan dyes pass through a central opaque layer , except where they are anchored by developer mole- cules . A positive color image slowly appears against a white back- ground on the far side of the material from the exposed surface .
Instant picture cameras
As the name implies , instant picture cameras use special film which self - develops a few seconds or minutes after exposure . There are two types of material in common use- material you have to peel - apart , and integral processing material .
With a camera designed for peel - apart material , such as shown right , you expose the picture on a piece of light - sensitive paper or film . You then pull a tab which brings the film into contact with a receiving paper and pulls the two sheets from the camera through a pair of spring - loaded rollers These rollers spread chemicals between the two surfaces . After an appropriate number of seconds the time varies according to the temperature - you peel the sheets apart . A positive , right - way - round image is printed on the receiving paper . You then either discard the negative or , if you have used a black and white film designed for printing , wash the negative and retain it . Polaroid peel - apart film packs , for black and white and . color , also fit specially designed direct viewfinder cameras , and attachments for 120 rollfilm single lens reflex or 5 × 4 ins sheet film cameras .
Integral - processing instant picture ma- terials are made by both Polaroid and Kodak . The two systems are similar , but incompatible . In both systems one multi- layer sheet is used both for the exposure and the final print . This is ejected from the camera immediately after exposure as a creamy looking blank print , on which a color image gradually appears .
Peel - apart instant picture film
Peel - apart instant film is most widely used on simple viewfinder cameras , such as shown above , right . Peel- apart film backs , above left , are also made to fit rollfilm single lens reflex cameras .
Cameras for integral processing
Polaroid SX - 70 series
Viewfinder
Focus control
Shutter release
Exposure control
Lens
Kodak EK series
Viewfinder
Shutter release
Lens
Polaroid SX - 70 system
Polaroid's integral - processing instant picture material forms a finished color photograph on the same surface that received the image . The image is reflected by a mirror inside the camera so that it is not reversed left - to - right on the final print .
The SX - 70 is a special type of single lens reflex . During focusing a face - down hinged mirror covers the film pack . Light is reflected from a mirror fixed to the rear of the camera so that the image is seen and focused on the back of the face - down mirror , as shown right . When you take a picture the mirror rises , seals off the eye - piece , and reflects the image on to the light - sensitive material .
Motorized rollers then eject the card , spreading re - agent chemical and light - proof white pigment between the processing lower layers and the top receiving layers . Gradually yellow , magenta , and cyan dyes released from below rise and permeate the white surface to form a visible color picture .
Kodak EK system
In the Kodak instant picture system , right , one side of the multi - layer coated plastic sheet is exposed to the image , while the finished picture forms on the oppo- site side . So to form the final image the correct way around , either the exposing surface must face the lens directly , or the image must be reflected twice before reaching it .
Light from the lens is reflected twice in the camera by fixed mirrors on to the sensitive material . You compose the picture and aim the camera by means of a separate , direct vision viewfinder .
After exposure the eighteen- layered material is ejected through rollers which spread reagent within the film . Yellow , magenta , and cyan dyes pass through a central opaque layer , except where they are anchored by developer mole- cules . A positive color image slowly appears against a white back- ground on the far side of the material from the exposed surface .
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