Heliography

The heliography or photogravure ( portmanteau formed from the Greek Ἥλιος hélios "sun" and γράφειν gráphein " draw (be) write") is the method developed by Joseph Nicéphore Niépce, which could produce the first permanent in the history of photography images.

Niépce in this respect experiments had begun in 1811, in 1822 he had made ​​the first light-resistant helio graphic copy of a graphic sheet. The experiment of 1826 is regarded as actual birth of photography, because it Niépce first time managed to create lasting photographic images by the camera. Niépce worked in 1829 with Louis Daguerre together. As the official birth of photography is 1839 with the public presentation of the daguerreotype.

Technique of heliography

Nièpce held in 1826 with a camera obscura and a surface coated with asphalt, 21 × 16 cm polished pewter plate a view from the window of his study fixed. The exposure time was about eight hours. On exposure to light of the asphalt is hardened, so that the subsequent "development" with lavender oil, and petroleum asphalt only the less exposed parts were removed. Thus, the image was both "fixed" and lightproof. The real goal of Niépce was these plates to etch then to get it by printing prints, but this is succeeded only contact prints of line drawings ( engravings, etchings ). He also used lithographic stones, glass plates, tin, zinc, copper and silver plated plates. In later experiments, he steamed the developed plates with iodine to blacken the shadows, then dissolved the remaining asphalt layer with alcohol and received so -contrast direct positives. Although the heliography reached far back Niépce not ready for application, but was later further developed by his nephew Claude Félix Abel Niépce de Saint -Victor. He succeeded in 1855 by means of the engraver Lemaître to etch the Heliografien and to try to produce prints, which laid the foundation for the later photogravure process.

Other early photographic processes

  • Daguerreotype ( 1835)
  • Talbotype (also calotype or Argyrotypie; 1835)
  • Ambrotype ( 1850 )
  • Tintype (also eindeutschend plate photography; 1850 )
  • Collodion wet plate ( 1850 ), History and evolution of photography
  • Wothlytypie (1864 )

Note: helio graphic coordinates, however, are a term used in astronomy.

384025
de