Tuesday 13 September 2011

Film Cameras-object






*** The forerunner to the camera was the camera obscura.[1] It was a dark chamber (in Latin, a camera obscura, demonstrating the etymology), "consist[ing] of a darkened chamber or box, into which light is admitted through a pinhole (later a convex lens), forming an image of external objects on a surface of paper or glass, etc., placed at the focus of the lens".In the 6th century, Greek mathematician and architect Anthemius of Tralles used a type of camera obscura in his experimentsThe camera obscura was described by the Arabic scientist Ibn al-Haytham (Alhazen) in his Book of Optics (1015–1021). Scientist-monk Roger Bacon also studied the matter The actual name of camera obscura was applied by mathematician and astronomer Johannes Kepler in his Ad Vitellionem paralipomena of 1604. He later added a lens and made the apparatus transportable, in the form of a tent Irish scientist Robert Boyle and his assistant Robert Hooke developed a portable camera obscura in the 1660s
The first camera obscura that was small and portable enough for practical use was built by Johann Zahn in 1685. At this time there was no way to preserve the images produced by these cameras apart from manually tracing them. However, in 1724, Johann Heinrich Schultz discovered that a silver and chalk mixture darkens under exposure to light. Early photography built on these discoveries and developments. The early photographic cameras were essentially similar to Zahn's camera obscura, though usually with the addition of sliding boxes for focusing. Before each exposure, a sensitized plate would be inserted in front of the viewing screen to record the image. The first permanent photograph was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris and building on Johann Heinrich Schultz's discovery about silver and chalk mixtures darkening when exposed to light. Jacques Daguerre's popular daguerreotype process utilized copper plates, while the calotype process invented by William Fox Talbot recorded images on paper.
The development of the collodion wet plate process by Frederick Scott Archer in 1850 cut exposure times dramatically, but required photographers to prepare and develop their glass plates on the spot, usually in a mobile darkroom. Despite their complexity, the wet-plate ambrotype and tintype processes were in widespread use in the latter half of the 19th century. Wet plate cameras were little different from previous designs, though there were some models, such as the sophisticated Dubroni of 1864, where the sensitizing and developing of the plates could be carried out inside the camera itself rather than in a separate darkroom. Other cameras were fitted with multiple lenses for making cartes de visite. It was during the wet plate era that the use of bellows for focusing became widespread.
The first color photograph was made by Scottish physicist James Clerk Maxwell, with the help of English inventor and photographer Thomas Sutton, in 1861
The electronic video camera tube was invented in the 1920s, starting a line of development that eventually resulted in digital cameras, which largely supplanted film cameras after the turn of the 21st century

A wide range of film and plate formats has been used by cameras. In the early history plate sizes were often specific for the make and model of camera although there quickly developed some standardisation for the more popular cameras. The introduction of roll film drove the standardisation process still further so that by the 1950s only a few standard roll films were in use. These included 120 film providing 8, 12 or 16 exposures, 220 film providing 16 or 24 exposures, 127 film providing 8 exposures (principally in Brownie cameras) and 35 mm film providing 12, 20 or 36 exposures – or up to 72 exposures in bulk cassettes for the Leica Camera range.
For cine cameras, 35 mm film was the original film format but 16 mm film soon followed, produced by cutting 35 mm in two. An early amateur format was 9.5 mm. Later formats included 8 mm film and Super 8

The introduction of films enabled the existing designs for plate cameras to be made much smaller and for the base-plate to be hinged so that it could be folded up compressing the bellows. These designs were very compact and small models were dubbed Vest pocket cameras ***





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