Camera Clues: A Handbook for Photographic Investigation

2. The History of Photography

2 THE HISTORY OF PHOTOGRAPHY The Development of the Photographic Process Ever since prehistoric times-when cave dwellers painted likenesses of animals they hunted on the walls of caves such as the Altamira caverns in SpainI-people have sought to make images of the world around them. Later developments such as the landscape paintings beautifully rendered on silk by ancient Chinese artists2 or portrait art (developed by the Egyptians and Romans and introduced, in the West, at the beginning of the Renaissance 3) continued the tradition. The growth of the middle class in the eighteenth century created a demand for artistic likenesses of people that were less expensive than the oil portraits commissioned by wealthy patrons. Miniature paintings satisfied the demand to an extent, but it was largely the silhouette-traced and filled in in black ink from a shadow cast by a lamp, or cut freehand from black paper by an artist using small, long-handled scissors-that first captured the mass market .4 Named for Etienne de Silhouette, a French minister offinance who was an amateur profile artist, these shadow portraits were at first one-of-a-kind originals (see Figure 2.1) until another Frenchman, Gilles Louis Chretien, invented in 1786 a multiple-image-making device called the Physionotrace.5 This apparatus was similar to a draftsman's pantograph, and to the device ThomasJefferson used to make instantaneous copies ofletters he was writing.6 When a pointer was traced over the lamp-cast profile, a system oflevers caused an engraving tool to reproduce the outline on a copper plate. Details offeatures and costumes could be added, and the plate could then be inked and printed to make many duplicate images. Soon artists and inventors began to speculate about optical devices that might produce images directly.7 Such an optical device-the camera obscura-was known in ancient times, but there was then no means of permanently recording the transient THE HLSTORY OF PHOTQGRi\PHY 5 Figure 2.1. Traced silhouettes were forerunners of later photographic techniques that also used light to record an image. (From an 1898 text, Magic: Stage /lJusions and smntific Diversions, Including Trick Photography.) image. As Leonardo da Vinci described the camera obscura in his note· books: "When the images of illuminated objects pass through a small round hole into a very dark room ... you will see on the paper all those objects in their natural shapes and colours. They will be reduced in size, and upside down, owing to the intersection of the rays at the aperture.'" Various portable models of the camera ohscura were developed, and in 1589 Giovanni Battista della Porta published a note on the advantage of using a lens instead ofa small hole. About 1665 Robert Boyle constructed a box-type model that could be extended or shortened, like a telescope, so that the image could be focused onto a paper placed across the back of the box directly opposite the lens. While scientists used the camera obscura for solar observations, artists adapted the device (using a mirror to correct the left· right reversal of the image) as an aid in drawing, since they could easily trace the projected image.9 About 1800, the first experiments in attempting to "fix" camera ohscura images were made in England by Thomas Wedgwood. He sought to copy paintings made on glass onto sheets ofpaper treated with silver nitrate. As demonstrated by C.w. Scheele in 1777, such silver compounds darken by the action of light. The great chemist Sir Humphry Davy wrote of his friend 6 CAMERA CLUES Wedgwood's experiments: "When the shadow of any figure is thrown upon the prepared surface, the part concealed by it remains white, and the other parts speedily become dark." With the painting on glass, "the rays transmitted through the differently painted surfaces produce distinct tints of brown or black, sensibly differing in intensity according to the shades of the picture ." Unfortunately, the resulting images were impermanent, and-due to their light sensitivity-could only be viewed by candlelight. Moreover, as Davy wrote, "the images formed by means of a camera obscura, have been found to be too faint to produce, in any moderate time, an effect upon the nitrate of silver." 10 It remained for the Frenchman Joseph Nicephore Niepce to produce the first permanent images made by the direct action of light. An amateur scientist and artist who was interested in...