At the heart of photography is the camera, a device that uses lenses to focus the image, a variable aperture to control the brightness of the light and a shutter that can open and close in a precise duration of time. The other component is a light-sensitive medium to capture the image.
In the early 1800’s when much effort went into developing a light-sensitive medium, the camera was nothing new. The camera obscura had existed for centuries. In fact, there’s a high likelihood that you have created a camera obscura.
When there is a solar eclipse it is too dangerous to look directly at the sun without looking through very dark sunglasses. As an alternative, we take a piece of cardboard, punch a hole in it, and project the image of the sun on the sidewalk. As the moon consumes the sun, the projected image shows the image of the crescent sun.
Shining light through a small whole is the principle of the camera obscura. If the light shines on a screen, an upside-down image appears.
The Chinese understood this principle as early as the 4th century BCE knew when they created a sundial with a small hole in the gnomon, the sail-like piece that casts it’s moving shadow on the plate. The hole projected a bright spot on the plate which enabled the Chinese to not only tell the time from the position of the shadow but also the date from the position of the bright spot.
The camera obscura was used to study optics and astronomy in the 16th century. But by 1567, the camera obscura was being used by painters as a drawing aid.
Time passed until explorations into light-sensitive materials in the early 1800s began to produce results.
Joseph Nicéphore Niépce created the heliographic process which used the Bitumen of Judea, a form of asphalt which was capable of capturing permanent images. Paired with the camera obscure, around 1827 he produced the earliest surviving permanent photograph.
Niepce’s associate was Louis Daguerre who. In 1839, took a different approach. He coated a copper plate with silver and exposed the silver to the fumes from iodine crystals, making the silver sensitive to light. Next came the exposure followed by development of the latent image with mercury vapor. There result was the daguerreotype. It was an instant success. Painters set down their paints and brushes and started making daguerreotype portraits, a process that was much faster and far less expensive.
Not long after the introduction of the daguerreotype, Henry Fox Talbot introduced the calotype negative and salt print processes 1841. Paper was coated with silver iodide which, when exposed in a camera, became the negative. After ‘fixing’ the image the semi-translucent paper negative cold be used to make any number of contact prints. The calotype process produced soft images compared to the extreme detail in daguerreotypes. But it had the advantage to make any number of prints whereas there could only be one daguerreotype.
In 1851 photography took the next step with the invention of the collodion process by Frederick Scott Archer and Gustave Le Gray. This is also known as the collodion wet plate process where a glass plate needed to be coated, sensitized, exposed and developed within fifteen minutes. Not only did photographers need to bring their camera, lenses and tripods with them but they also need to bring a darkroom. These wet plates combined the exquisite detail of a daguerreotype with the ability to make numerous prints.
In 1851 Richard Maddox enhanced the collodion process by creating day glass plates coated with a light-sensitive gelatin emulsion. These could be created and stored until they were ready to be used. Later, Charles Harper Bennett brought them to market.
The next development was to coat celluloid film with light-sensitive emulsions. Eastman Kodak patented roll film in 1888 marking the start of film photography as we have come to know it. Now the scene is set for the pioneering photographers who shaped the course of photography’s struggle to be accepted as a valid art form.
(115)
