Something to Know More About Modern Photography
18th century photography
The invention of photography's first practical process was another Frenchman, Niepce's counterpart, Louis Daguerre. While Joseph Nicephore Niepce was trying out ways and means to capture images, Daguerre was also experimenting with various chemicals and techniques. In 1829, Daguerre developed a partnership with Niepce to explore ways to develop and improve Niepce's technique. But it took another decade before Daguerre finally found a way to bring down exposure time to 30 minutes or less as compared to the several hours it took earlier, and prevent the developed image from disappearing.
The Daguerreotype
In the meantime, Niepce passed away and Daguerre continued his process of experimentation with the assistance of Niepce's son. In 1837, he developed a process which was a more effective and convenient way of photography; he name the technique the 'Daguerreotype' after himself and unveiled the 'first practical photographic process' in 1839.
The Daguerre Process used a sheet of copper plated with silver and iodine vapor to coat the copper sheet with light sensitive silver iodine. This plate was placed inside a camera and exposed to light such that the image was painted. The exposed image in the camera was then developed by mercury vapor and fixed permanently by bathing it in a solution of silver chloride, thus creating a lasting image which remained unchanged even when exposed to light.
The duo sold the rights of the 'Daguerreotype' to the French government in 1839; by 1850 the Daguerreotype had gained such popularity that in New York City alone, there were close to seventy Daguerreotype Studios.
The Calotype - Negative to Positive process
There were several ongoing techniques and experiments with cameras and photography in the early and mid 1800s. In 1840, a different process called the Calotype was perfected by Henry Fox Talbot, an Englishman, a contemporary of Daguerre and a mathematician and botanist in his own right. Both Daguerre and Talbot used sliding boxes to focus but the cameras were more different from Zahn's pinhole cameras.
Talbot created the first negative by first using a silver salt solution to sensitize the photographic paper which was then exposed to light. The background became black on exposure and the subject was washed in tones of gray color. This became the paper negative which were then used by Talbot to make contact prints, when the reversing of light and shadows created detailed pictures. By perfecting this process, Talbot was on his way to making the paper negative process, naming it the Calotype, which in Greek meant 'beautiful picture'.
The 1850s to 1900
This period saw in quick succession several new techniques such as:
• Wet Plate Negatives - Where paper was used earlier, the medium switched to glass which was coated with silver salts using collodion, creating a wet plate which produced detailed and more stable negatives. The English sculptor, Frederick Scoff Archer invented this method in 1851. However, this required a portable darkroom for developing the wet plates because the emulsion would dry very quickly.
• Tintype - The base for light-sensitive material was provided by a thin sheet of iron which produced a positive image. This patent developed by Hamilton Smith in 1856 introduced photography to the modern world in a big way.
• Dry Plate Negatives - This was the breakthrough photography needed. A dried gelatin emulsion coated glass negative plate was invented in 1979 that needed no portable darkrooms; technicians could develop the photographs at any time. This dry process made hand-held cameras possible because the light absorption was very rapid.
• A flexible and unbreakable film that could be rolled was invented by George Eastman in 1889. The famous Eastman film, that was a cellulose nitrate with a coating of emulsion, was the precursor to the mass production of the box camera.
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