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1. Presention history of photography.ppt
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- 2. • The wordphotography is derived from the Greek words: Photos=light Graphein=writing , drawing Photography is writing with light.
- 3. Definition • Photography isthe art to fix from the action of the light, the image of an object onto a sensitive surface (paper, film/negative/pellicule, plate…)
- 4. • 1839, isthe year of the invention of photography. • Photography is half art half science.
- 5. Camera obscura • Sinceat least the time of Aristotle, it had been known that the rays of light passing through a pinhole would form an image. • The 10th-century Arabian scholar Alhazen described the effect in detail and told how to view an eclipse of the sun in a camera obscura (dark chamber) a darkened room with a pinhole opening to the outside.
- 6. • By thetime of the Renaissance, a lens had been fitted into the hole to improve the image, and the room-sized device had been reduced to the size of a small box that could be easily carried. • The camera obscura became a drawing aid that enabled an artist to trace an image reflected onto a sheet of drawing paper.
- 9. Inventors of photography •1- Joseph Nicephore Niepce:(1765-1833) • He was the first to fix the photographic image (1826) using the camera obscura. • He experimented with silver chloride, which he knew darkened on exposure to light, but then turned to bitumen of judea, a kind of asphalt that hardened when exposed to light.
- 10. • He coateda sheet of pewter, and placed it in a camera obscura aimed through an open window at his courtyard and exposed it for 8 hours. • The exposure time was so long, that the sun moved across the sky and illuminated both side of the courtyard. • He named the process heliography(from Greek helios = sun, and graphos =drawing). • After his death, Daguerre continued to experiment.
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- 12. • 2- LouisJacques Mande Daguerre(1799-1851) • Soon he had discovered a way of developing photographic plates, a process which reduced the exposure time from 8 hours down, to half an hour. • His invention called Daguerreotype, was made on a highly polished surface of silver that was plated on a copper sheet and developed after exposed with heated mercury.
- 13. • The daguerreotypewas very popular in its time. • Each plate was unique and there was no way of producing copies except by rephotographing the original.
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- 15. • 3- WilliamHenry Fox Talbot(1800-1877). • His first experiments had been with negative silhouettes made by placing objects on sensitive paper and exposing them to light.(photogramme). • In 1840 Talbot announced a technique that became the basis of modern photography. • He called his invention a calotype( after the Greek, kalos = beautiful, and typos = impression).
- 19. • An infinitenumber of positives could be made from a single negative, which was to provide the answer to the daguerreotype problem.