Essay on Photograph: Photography and Camera Obscura

Submitted By swan54
Words: 1267
Pages: 6

photograph

Camera obscura

George Eastman

Photography essay.
Example of wet collodian plate

Calotype

Example of tintype photography

20G Mr. Argue

By Chris swan
Photography is the process of creating still or moving pictures by recording radiation on a sensitive medium like film or an electronic sensor. In this essay I will be explaining Camera obscura, calotype, the collodian process, tintype images and a man who revolutionised photography George Eastman. These key points helped get photography to where it is today and how advanced it will be in the future.
Firstly, Camera Obscura (Latin for a ‘’dark room’’) is a dark box or room with a hole in one end. If the hole is small enough, an image can be seen on the opposite side. This phenomenon was known by thinkers as early as Aristotle around 300 BC. Many sources state that Roger Bacon invented Camera Obscura just before the year 1300. Bacon popularized Camera Obscura, by using it to view solar eclipses.
Next, calotype is one of the first photographic processes invented in the nineteenth century. It was the first negative-positive system created, and was widely used in France and England. Even though the word “calotype” is often used to describe both the positive salted-prints and the negative print, it should refer only to the negative. During the 1830’s, a man named William Henry Fox Talbot from England developed this process of capturing light image on a sensitized paper and introduced it to the public in 1840. He named the process “calotype,” but it was also called “Talbotype” after his name. The calotype used a silver-sensitized paper, also the calotype produced images that were softer, less sharp and more atmospheric due to the presence of fiber in the paper. The calotype was print medium. It is a negative from which multiples positives can be made by using salted-paper. Many nineteenth-century photographers and critics criticized the bad and blurry images from the calotype process. This technical difficulty, along with the restriction of Talbot’s patent on the process in 1841, made the calotype less popular among the public and also restricted its commercial use.
Now we will look at the collodian process is an early photographic process, invented by Frederic Scott Archer. It was introduced in the 1850s and by the end of that decade it had almost entirely replaced the first practical photographic process, the calotype. During the 1880s the collodian process, was largely replaced by: Gelatin, Dry plates, and Glass plates. With the photographic emulsion of silver halides it can be suspended in gelatin. The dry gelatin emulsion could be made much more sensitive, by reducing exposure times.

Next, Tintype photos were photos with the image on a metal surface, instead then on glass or paper. Tintypes images were negatives on iron, coated with black paint, lacquer or enamel. The process for Tintype cameras would normally hold a stack of unprocessed tin plates inside the camera. They would have a device such as a rubber sucker and moving arm to raise each of the plates in turn to be exposed. After exposure, the plate would be dropped through a slot in the base of the camera into a tank that held chemicals for immediately processing the image. The chemicals would be a high strength solution that would develop and fix an image. This was designed so that the developer would work faster than the fixer, and the image would be ready to wash in about a minute. The results were often low quality, so studios tended not to use tintypes, except when a small 'gem' tintype images (1 x 1 in) were mounted onto a card.
Finally, George Eastman was an American inventor and philanthropist. He played a leading role in transforming photography from an expensive hobby of a few assistances into an inexpensive and very popular pastime. He was born in Waterville, New York, and was self-educated. In 1884 Eastman patented the first…