Photography as a medium is less than 200 years old. But in that brief span of history, it has evolved from a crude process using caustic chemicals and cumbersome cameras to a simple yet sophisticated means of creating and sharing images instantly. Discover how photography has changed over time and what cameras look like today. 카지노사이트
The first “cameras” were used not to create images but to study optics. The Arab scholar Ibn Al-Haytham (945–1040), also known as Alhazen, is generally credited as being the first person to study how we see. He invented the camera obscura, the precursor to the pinhole camera, to demonstrate how light can be used to project an image onto a flat surface. Earlier references to the camera obscura have been found in Chinese texts dating to about 400 B.C. and in the writings of Aristotle around 330 B.C.
By the mid-1600s, with the invention of finely crafted lenses, artists began using the camera obscura to help them draw and paint elaborate real-world images. Magic lanterns, the forerunner of the modern projector, also began to appear at this time. Using the same optical principles as the camera obscura, the magic lantern allowed people to project images, usually painted on glass slides, onto large surfaces. They soon became a popular form of mass entertainment.
German scientist Johann Heinrich Schulze conducted the first experiments with photo-sensitive chemicals in 1727, proving that silver salts were sensitive to light. But Schulze didn’t experiment with producing a permanent image using his discovery. That would have to wait until the next century.
The First Photographers
On a summer day in 1827, French scientist Joseph Nicephore Niepce developed the first photographic image with a camera obscura. Niepce placed an engraving onto a metal plate coated in bitumen and then exposed it to light. The shadowy areas of the engraving blocked light, but the whiter areas permitted light to react with the chemicals on the plate.
When Niepce placed the metal plate in a solvent, gradually an image appeared. These heliographs, or sun prints as they were sometimes called, are considered the first photographic images. However, Niepce’s process required eight hours of light exposure to create an image that would soon fade aw 바카라사이트
Fellow Frenchman Louis Daguerre was also experimenting with ways to capture an image, but it would take him another dozen years before he was able to reduce exposure time to less than 30 minutes and keep the image from disappearing afterward. Historians cite this innovation as the first practical process of photography. In 1829, he formed a partnership with Niepce to improve the process Niepce had developed. In 1839, following several years of experimentation and Niepce’s death, Daguerre developed a more convenient and effective method of photography and named it after himself.
Daguerre’s daguerreotype process started by fixing the images onto a sheet of silver-plated copper. He then polished the silver and coated it in iodine, creating a surface that was sensitive to light. Then he put the plate in a camera and exposed it for a few minutes. After the image was painted by light, Daguerre bathed the plate in a solution of silver chloride. This process created a lasting image that would not change if exposed to light.
In 1839, Daguerre and Niepce’s son sold the rights for the daguerreotype to the French government and published a booklet describing the process. The daguerreotype gained popularity quickly in Europe and the U.S. By 1850, there were over 70 daguerreotype studios in New York City alone.
Negative to Positive Process
The drawback to daguerreotypes is that they cannot be reproduced; each one is a unique image. The ability to create multiple prints came about thanks to the work of Henry Fox Talbot, an English botanist, mathematician and a contemporary of Daguerre. Talbot sensitized paper to light using a silver-salt solution. He then exposed the paper to light. 온라인카지노
The background became black, and the subject was rendered in gradations of gray. This was a negative image. From the paper negative, Talbot made contact prints, reversing the light and shadows to create a detailed picture. In 1841, he perfected this paper-negative process and called it a calotype, Greek for “beautiful picture.”
Other Early Processes
By the mid-1800s, scientists and photographers were experimenting with new ways to take and process pictures that were more efficient. In 1851, Frederick Scoff Archer, an English sculptor, invented the wet-plate negative. Using a viscous solution of collodion (a volatile, alcohol-based chemical), he coated glass with light-sensitive silver salts. Because it was glass and not paper, this wet plate created a more stable and detailed negative.
Like the daguerreotype, tintypes employed thin metal plates coated with photosensitive chemicals. The process, patented in 1856 by the American scientist Hamilton Smith, used iron instead of copper to yield a positive image. But both processes had to be developed quickly before the emulsion dried. In the field, this meant carrying along a portable darkroom full of toxic chemicals in fragile glass bottles. Photography was not for the faint of heart or those who traveled lightly.
That changed in 1879 with the introduction of the dry plate. Like wet-plate photography, this process used a glass negative plate to capture an image. Unlike the wet-plate process, dry plates were coated with a dried gelatin emulsion, meaning they could be stored for a period of time. Photographers no longer needed portable darkrooms and could now hire technicians to develop their photographs, days or months after the images had been shot.