What are daguerreotype plates made of

Part 3/10: The great inventors of the 19th century

The first person who succeeded in capturing an image of reality on a light-sensitive plate was Joseph Nicéphore Niepce (1765–1833). For years he made countless experiments with chemical substances and tested their reaction in terms of sensitivity to light and durability in a camera obscura.

Joseph Nicéphore Niepce (1765–1833)

The Frenchman only achieved the long-awaited breakthrough more than 30 years after the first attempts, when Niepce used asphalt as a light-sensitive layer in 1824. The asphalt was dissolved in petroleum and then applied thinly to a glass, stone, silver, tin or copper plate. During the exposure, the asphalt hardened, while the unexposed areas could be removed from the plate with a solvent. In this way, an image was created that was etched or engraved in the areas freed from the asphalt layer. Finally, prints could be made from the inked printing plate. Niepce called these plates exposed in this way Heliographies.

Cardinal Amboise, heliography, 1827

The first photo that has survived to this day was finally taken in Joseph Nicéphore Niepce's house in Gras en Châlon in 1826. The exposure time for this shot was an incredible eight hours.

Niepce, 1826: The world's first surviving photograph.

Louis Jacques Mandé Daguerre (1787–1851), a famous theater painter in France, also dealt intensively with the idea of ​​photography. He tried to work with Niepce, but Niepce refused for the time being. Since Niepce's discovery of heliography at this time did not find much public approval, Niepce was ultimately compelled, despite strong concerns, to sign a partnership agreement with Daguerre in 1829.

Louis Jacques Mandé Daguerre (1787-1851)

But constantly divided over research methods and suggestions from each other, the two could not show any further new developments until Niepce finally died in 1833. Daguerre continued his experiments and discovered almost by chance in 1835 that the exposure of an iodized silver plate resulted in an invisible image that could be developed with the help of mercury vapor and thus made visible. With this process, he was able to rapidly reduce the exposure time from around eight hours to an average of seven minutes. Just two years later he was able to fix the picture with a simple saline solution.

The first original Daguerre camera to arrive in Germany: The camera housing consists of two sliding wooden boxes that can be slid into each other to focus the subject. A simple metal flap closes the strongly dimmed lens, which consists of a simple achromatic lens. This camera is now in the Deutsches Museum, Munich.

To this day, art history debates whether Daguerre can be called the sole inventor of photography. What is certain is that he took the decisive step towards fixing pictures on a picture carrier, but without Niepce's preparatory work he would probably never have succeeded.

William Henry Fox Talbot (1800–1877)

Parallel to the developments on the continent, the English were not idle either: in 1835 William Henry Fox Talbot (1800–1877) succeeded in producing a lightfast image. But there the Daguerreotype produced a much better image, he could not assert his claim as the actual inventor of photography before Daguerre. In September 1840, however, Talbot took a decisive step. He developed the negative-positive process, the so-called Calotype: In this process, a negative is first produced from the image to be reproduced. On the negative, the image changes inversely to the degree of brightness and the color of the light. Dark becomes light, light becomes dark.

Calotype (paper negative), view in Rome, ca.1855

Salt paper print of the negative, faded

In order to obtain a true-to-original image, the process must then be reversed again: A positive is developed from a negative - the photo. This Negative-positive process enabled limitless reproduction of an image from a negative. Furthermore, with his groundbreaking process, Talbot was able to reduce the exposure time of a photograph to an average of one minute, six minutes faster than Daguerre. As early as 1844 Talbot published his first famous book entitled “The Pencil of Nature”, which contained 24 original calotypes.

Gate in front of Abbortford Castle from "Sun Pictures in Scotland"

From around 1860 the calotype became the basis of all essential photographic processes and thus replaced the daguerreotype.

The author Julia Schneider studied art history and actively supported the Städel's press department during her internship, which lasted several months. As a native of Hamburg, her heart beats for Caspar David Friedrich.

You can find out how rapidly the development of photography continued in the 19th century in part 4 of our series on photography techniques.

Techniques of Photography: Photography in Focus, Part 1

Photography Techniques: The Camera Obscura, Part 2

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