Phil Borges
Susan Fenton
Lynn Geesaman
Rolfe Horn
Kenro Izu
Pedro Meyer
Madoka Takagi
Mary Van Cline
Paul Paletti - July 2000
Since the announcement of the invention of photography in 1839, a variety of technological processes have been used to produce photographic images. Although photographs have been produced on a variety of materials, including silver-plated copper plates and glass, photographs produced on paper quickly came to be the dominant format for photography. Generally, paper was coated with chemicals that would be affected by exposure to light. There was a great deal of experimentation regarding the particular types of chemicals (metal halides) which could be adapted to these processes. After this initial period of experimentation lasting about 50 years, most of the basic photographic processes were developed. The various materials used have evolved and been refined as a result of several factors, including cost of materials, improved manufacturing processes, speed of production, light sensitivity, general aesthetics and popularity. Since the 1920s, the dominant photographic printing materials have been gelatin silver prints, which are the black and white photographs we encounter every day. But in the last 20 years, a resurgence of interest has occurred in earlier processes employing different light sensitive materials, such as platinum and palladium. These processes have different tonal scales, colors and textures and are much less convenient to use than the modern photographic materials. This combined historical and aesthetic interest can be seen in a number of the works of the photographers represented in this show.
GELATIN SILVER PRINTS
Gelatin silver prints use silver chloride and silver bromide suspended in a gelatin emulsion. These photographic materials are extremely sensitive to light, allowing negatives to be enlarged to virtually any size in a darkroom. Two variations employing gelatin silver prints are the selectively toned and hand-colored prints.
SELECTIVELY TONED PRINTS
After creating a gelatin silver print, some photographers bathe the print in selenium, sepia or gold toning solutions. These coat the silver halide grains with the metals contained in the toning solution, resulting in changes to the color of the print. The black and gray tones may be changed to various hues of golden browns and purples. Selective toning involves masking various parts of a print so the toning solution cannot penetrate and change the color of the masked areas.
HAND-COLORED PRINTS
Starting with a matte surface gelatin silver print, the photographer uses special oil based pigments to paint layers of colors on to the photograph.
PLATINUM AND PALLADIUM PRINTSKenro Izu, Dick Arentz, Madoka Takagi
Invented in the 1870s, this process employs platinum or palladium instead of silver in the photographic emulsion. The result is a very soft and long tonal range of rich grays. These materials are much less sensitive to light than modern photographic emulsions, and only contact prints, not enlargements, are possible. The negative must be placed directly against the platinum or palladium paper, and exposed to sunlight or an arc lamp. The print is therefore the same size as the negative. The only way to produce a large print is to start with a large negative. The photographers represented in this show are using large view cameras, which produce negatives up to
PHOTOGRAVURE
Invented in the 1850s by William Henry Fox Talbot, one of the original inventors of photography, and perfected in 1879, this photomechanical process etches a photographic image into a copper plate. A specially treated light-sensitive gelatin paper is exposed to a positive transparency. The gelatin layer is then transferred on to the copper plate, forming a bas-relief etching resist-- thick in what will be the light areas of the print, and thin in the shadow areas. The plate is then immersed in a series of acid baths, which first etch through the thinnest areas of the gelatin resist, and then progressively through the thicker gelatin layers. A thick printing ink is forced into the recesses of the etched plate, and the surface wiped off. A piece of paper is placed on top of the plate, and it is run through an intaglio printing press. The technique of printing the plate is the same as used for producing aquatints and other etchings. The photogravure process, in its commercial version, is used today to print cereal boxes, labels and other items in extremely large quantities.
COMPUTER GENERATED PHOTOGRAPHY
Computers and software have provided the most recent revolution in the technology and aesthetics of photography. Using these new techniques, photographers can combine different photographs into a single print and alter virtually any aspect of the imagery.
DIGITAL INK JET / IRIS PRINTS
Using a visual image translated into a digital computer file, these processes use special ink jet printers to produce color or black and white prints on paper up to 35" x 47" in size. Iris printers spray the inks (either monochrome or four colors) through nozzles at the rate of four million droplets per second on to paper or other material attached to a rotating drum. These droplets are about the size of red blood cells, and are sprayed in a precisely controlled manner to form different colored dots of varying sizes. The result is a virtually continuous toned.
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