chapter

1

What Is Photography?

The painter constructs,

the photographer discloses.

—SUSAN SONTAG

You don't take a photograph,

you make it.

—ANSEL ADAMS

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without an understanding of how it was accom-plished. It is clear that scientists in the Western world from at least the time of Leonardo da Vinci(c. 1490) were aware of the camera obscura, and at some point it was discovered that the image

There are two sides to photography. First, photography is the capture and display of images by means of fi lm or an electronic

sensor, and, second, photography is the art of tak-ing and presenting photographs. As commonly practiced, photography is inseparable from cam-eras. Of course, photography means “writing with light” and writing is really the operative word. When photography was invented in 1839, the thing that was discovered was the means for per-manently capturing images. Cameras of various kinds had, in fact, been available for centuries.

� e original camera, known as the camera obscura (see Figure 1.1), was nothing more than a dark room with a small hole (aperture ) in one wall and an inverted image on the opposite wall created by light rays passing through the aperture. � e wonderful image-forming property of a small aperture was noted by the philosophers Mo-Ti in China and Aristotle in Greece in the 5th and 4th centuries , respectively, although apparently

FIGURE 1.1. The camera obscura was used by Reinerus Gemma-Frisius in 1544 to observe an eclipse of the sun.

2 chapter

daguerreotypes, unfortunately, could not easily be reproduced. Th e striking images obtained by Daguerre were an instant hit, however, and most contemporaries considered him to be the inventor of photography. (See Figure 1.2.)

In marked contrast , Talbot ’s images were ini-tially unpleasing because the (bright) exposed ar-eas were found to be dark on the paper. In other words, a negative image was produced. Th at turned out to be a great advantage, however, because the negative could be combined with another sheet of sensitized paper and exposed to light to produce a positive copy, and that procedure could be repeat-ed to produce multiple copies. Of course, paper is translucent rather than transparent, and it was not until the 1850s that transparent negatives could be obtained. Th e terms photography and photograph are usually attributed to Sir John Herschel , who included them in a paper that he read to the Royal Society of London in 1839. Herschel also deserves credit for advancing photographic science by dis-covering how to stabilize silver images; however, credit for the name photography is controversial. Th e term photography may actually have been in-troduced earlier by an artist named Hercules Flor-ence working in Brazil in 1833. Florence , who used sensitized paper to copy drawings, did not report his work, and as a consequence, he had little infl u-ence on the development of photography.

For the next 160 years, silver-sensitized paper and fi lm coupled with the negative/positive pro-cess, dominated photography; and it was only af-ter the year 2000 that photoelectric detectors and powerful, yet inexpensive, computers challenged fi lm-based photography. Replacing fi lm with sen-sors and computer memory has not yet basically changed photography; however, computer ma-nipulation of images has turned out to be a rev-olutionary development. Even images captured on fi lm are now routinely scanned into comput-ers and digitized so that they are also subject to modifi cation. If computer image manipulations were limited to the types of things that photogra-phers were already doing in the dark room to cor-rect exposure, hold back or burn in areas, change

quality and intensity could be improved by en-larging the aperture and inserting a convex lens of the appropriate focal length . Th e portable camera obscura, a box with a lens on one side and some means of viewing the image, became popular with artists as an aid in representing perspective in paintings. For example, the 16th-century Dutch painter Johannes Vermeer (1632–1675) almost certainly used a camera obscura to see the correct representation of perspective for his paintings. By the 19th century these devices were essentially box cameras without photographic fi lm .

In the early 19th century, many individuals were experimenting with sensitized materials that darkened when exposed to light and produced fl eeting images, so proper credit for the invention of photography is diff use and controversial. Pho-tography as we know it dates from 1839 when two men independently reported processes for captur-ing images in the camera obscura . Th eir disclo-sures initiated explosive developments in image-making around the world. Th e Frenchman Louis Mandé Daguerre discovered a method for produc-ing a permanent image on a silver surface; while, in England, Henry Fox Talbot created permanent images on paper treated with a mixture containing silver chloride . In Daguerre ’s images, the areas ex-posed to light and properly processed were highly refl ecting; and, therefore, there was a natural (pos-itive) appearance though, of course, without color (monochrome). Th ese images, which were called

FIGURE 1.2. Louis Mandé Daguerre (left ) and Henry Fox Talbot (right).

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do? Is there any merit in maintaining photography with minimum manipulation for recording the world as it is? Th e future will tell. In fact, “truth” is found in some novels and paintings and in some photographs, but it must be tested and verifi ed by wise readers and observers.

Questions raised by the concepts of reality and truth in visual images are much more complex than may be thought. Later in the book I discuss the operation of the human visual system and its relation to our awareness of the world. It is fair to say that our eyes and brain create the illusion of a full-color, three-dimensional world. It is an illu-sion, because the images projected on the retinas of our eyes do not provide enough information for the construction of a unique worldview. Th e brain fi lls in details based on a sort of automatic infer-ence system that is infl uenced by both the evolu-tion of the human brain and the experience of the individual. Th e result is that we see, at fi rst glance, petty much what we expect to see. One should also realize that digital cameras basically compute pictures from captured light. Th e computation is not straightforward, and there is a lot of room for “enhancement” of the fi nal image. Th e new fi eld of computational photography is infl uencing the images produced by our cameras and the special eff ects we see in movies. It is an interesting time to be alive and maybe a little disturbing as well.

Further Reading

N. Rosenblum. World History of Photography, Th ird Edition. New York: Abbeville Press, 1997. (Th is is a tour of photography from 1839 through the fi lm era, including both art and the technical details.)

M. R. Peres (Editor). Focal Encyclopedia of Pho-tography, Fourth Edition. Amsterdam: Elsevier, 2007. (Although it is uneven and already some-what dated, this text provides extensive cover-age of theory, applications, and science.)

contrast , etc., there would be no fundamental change in photography. But now the changes can be so extensive and subtle that the boundaries of photography are continuously being tested.

It has been said that photographers reveal while artists create. Software for manipulating photo-graphic images and even creating realistic images from scratch is fundamentally changing this equa-tion. Illustrators using computer graphics have al-most unlimited ability to produce realistic images of any type. Photojournalists, on the other hand, must have their creative inclinations severely lim-ited by a code of professional ethics and perhaps by authentication software that can spot even mi-croscopic changes in digital images.

Anyone who has viewed recent movies knows that amazing things can be done to produce re-alistic images of things that never existed. Th e opening scenes in Day After Tomorrow show a fl ight over ocean, ice, and cliff s in Antarctica. It is beautiful and impressive. How was it done? A helicopter fl ight over those remote areas would be costly and dangerous, so the producer decided to create the scenes entirely with computer graph-ics. And what about the magnifi cent scenes in the epic Troy? Does anyone believe that 1000 or even 100 ships were constructed, or that 75,000 Greek warriors took part in the battle? We can all enjoy the endless possibilities for image-making, but we can no longer (if ever we did) believe in what theimages show.

So, ultimately, what is photography? Does it matter that wrinkles can be removed from faces and heads can be switched? Do we care if it is easy to move an alligator from a zoo to a natural area or a hummingbird from a feeder to a fl ower? Th ese tricks are still rare enough that gullible observers may marvel at how such “diffi cult” photographs could be obtained. I think we are seeing the emer-gence of a new art form, but I am not sure where that leaves photography. Will “pure” photography remain when everyone has an incentive to im-prove the images they obtain and it is so easy to

what is photography? 3

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