Before we begin to look at the technical details of photography it is interesting to take a look at how photography has developed over the years, and to get an understanding of how different techniques have developed and faded away over time.
We usually think of photography as beginning at the end of the Victorian age and progressing from huge black-and-white cameras to film colour cameras and finally to modern digital cameras. In truth the basic scientific knowledge needed to build a camera has been around for centuries, with even the ancient Greeks and Chinese building very primitive cameras 2,500 years ago.
At the most basic level a camera is a sealed box with a small hole on one side. According to basic laws of physics and optics this will lead to an image of the surroundings of the box appearing on the inside of the box. Examples of this effect can be found naturally in some caves, or even when the light shines through small holes in curtains.
This might not seem very useful – how can you see an image inside a closed box? But let’s imagine taking a very large box, we could even place a door and let it become a room, and now imagine making a small hole in the wall of this box or room. According to the same laws of optics, we now see an image of our surroundings projected in the room. This is not quite a camera, since we still can’t record the image very easily, but it is an interesting way of projecting light, and even offered early astronomers a safe way to study objects like the Sun.
This phenomena is known as a camera obscura, and structures taking advantage of it have been built for centuries. Often used for entertainment or for astronomical purposes, such rooms still exist, and you can even construct one in your own home. The image above shows the image formed inside a camera obscura in Stade, Germany.
Camera obscura was a pretty cool technique, but it had one big problem – no one knew how to capture the image inside so that it could be recorded and reproduced. This would have obvious applications in espionage, warfare or simply reproducing information. Various solutions were developed, usually involving mirrors and lenses to project the light in some way so that it could be manually recorded by tracing or drawing.
During the Middle Ages various materials were discovered that would react in some way (often by changing colour) when exposed to light. Despite some evidence of experimentation, nobody successfully used these light sensitive materials to record images from a camera obscura until around 1800, when Thomas Wedgwood used silver nitrate to produce the first known attempt at photography. These early images had to be kept in darkness, as any further exposure to light would destroy the photograph.
The very first permanent photograph, an image of an engraving of Pope Pius VII, was taken in 1826 by Frenchman Nicephore Niepce. Using light sensitive materials to capture the image and an exposure which apparently lasted for several days he was able to create a photograph that would not fade away. Sensing commercial opportunities he partnered with Louis Daguerre, and set about developing an improved photographic process. After his death in 1833 his partner Daguerre took over his work, and developed a complete photographic process needing an exposure of just a few minutes. His work was presented to the French Academy in 1839 and, with the support of the French government, Daguerrotype photography became commercially successful.
A daguerrotype differs from today’s photographs in many ways. Rather than appearing on paper (or a computer screen) daguerrotypes were formed on a reflective surface, usually a metal sheet coated in silver. The image would appear to float on the surface of this plate, in a similar way to modern holograms. A daguerrotype is also highly fragile, and can easily be destroyed even if brushed lightly. For this reason they are usually protected behind a glass screen. For twenty years daguerrotype photography was the most common form of photography, and several million daguerrotype machines a year were produced in their peak years.
As chemistry advanced and new chemical processes for recording light were developed the daguerrotype was replaced by the cheaper and improved collodion process, which was in turn superseded by gelatin plates around the 1880s. At the same time advances in recording colours (rather than just shades of light and dark) were made. With the field of photography rapidly developing, and growing middle classes in Europe and America keen to purchase cameras for themselves, the stage was set for one of the most important figures in the history of photography, George Eastman.
George Eastman, an American born in New York in 1854, bought his first camera at the age of 24 to record a planned vacation to the Caribbean island of Santo Domingo. He never made it to Santo Domingo, instead becoming obsessed with building an improved camera. His focus on simplifying the camera paid off, and he developed and sold the first mass produced camera films, incorporating the Eastman Kodak company in 1892. Over the next few years “Kodak” cameras became wildly successful, selling hundreds of thousands of cameras a year. George Eastman died a wealthy man in 1932 (with a fortune worth more than $1 billion in today’s money), and his Kodak company would be synonymous with photography until its’ recent bankruptcy in 2012.
Kodak, and rival companies such as FujiFilm in Japan, built a business model around photographic films. Cameras were sold cheaply, and profits were made through selling and processing the films. This strategy worked well for a century, until the decline in film revenues at the beginning of the 21st century led to the need to restructure the business model.
The reason for the decline in film sales was the rapid adoption of digital cameras. This new type of camera was born in the space race in the 1950s and 60s. As the US and USSR raced to put satellites in orbit around the world, a new type of remote espionage became possible. Understandably, retrieving films from space was quite a technological challenge, and this spurred the need to find a new way to capture photographs and transmit them from orbit to the ground. The solution to this was the development of the first digital cameras, with the first launched into orbit in 1976.
In the late 1980s portable digital cameras began to become commercially available, first in Japan in 1989 with Fujifilm’s DS-X, and then in the US as Kodak launched the DCS (Digitial Camera System). The rapid development of computer power and memory in the 1990s led to falling prices and improved performance, and the market for digital cameras exploded at the start of the 21st century. Sales of digital cameras have rapidly risen, dominating the world of photography and virtually wiping out the need for analog devices.
As technology and software continues to progress, since 2010 even sales of digital DSLR cameras are in decline, being outstripped by smartphone cameras. We now live in a world with billions of cameras, where once bulky and heavy cameras have been shrunk to tiny sizes, and the Internet allows instant sharing to thousands or even millions of viewers. Today, more and more software and advances in image processing algorithms are making up for the limitations of optical hardware. As technology continues to progress over next few years it’s likely that software will come to dominate photography even more – enabling novel concepts such as combining images from multiple cameras to produce 3D images, or allowing parameters such as focus to be modified after the photograph has been captured.