William Henry Fox Talbot (1800-1877), the inventor of photography on paper, was given crucial support by his colleague Sir John Herschel (1792- 1871). Fellows of The Royal Society, the two men made fundamental contributions to optics, chemistry, light, and mathematics. Both were humanists of diverse interests and had strong role models in women. For Talbot, it was his mother, Lady Elisabeth Feilding. Herschel learned some of his earliest science from his Aunt, Caroline Herschel; his wife, Margaret, was an active participant in his work. During the pre-history of photography, Mrs. Fulhame, Thomas Wedgwood, Sir Humphry Davy, and Nicephore Niepce demonstrated its potential. The question is why, rather than how, was photography invented and announced in 1839? The camera and the chemistry necessary for the art's invention co-existed for many decades. Frustrated in trying to sketch with Wollaston's camera lucida, Talbot conceived of photography; Herschel avoided making photographs because he was an expert draughtsman adept with the camera lucida. Herschel, following inductive reasoning, made seminal contributions to the field of photochemistry; he invented the cyanotype process and was the first to apply hypo to fix photographs. Talbot learned from his own photographs and grew into being the first photographic artist. Talbot and his rival, Louis Daguerre, mirrored the competitive economic race and differences in support of science and art between France and Great Britain. By the Great Exhibition in 1851, Herschel and Talbot had been forcefully removed from work in photography. Herschel's health was broken in service as Master of the Mint. He remained an important influence on other photographers, including Anna Atkins, Charles Piazzi Smyth, and Julia Margaret Cameron. Talbot learned from experience in photographic book publishing that silver photographs could never be made permanent. He applied his efforts to perfecting photoglyphic engraving, a forerunner of photogravure; he also invented the photographic halftone.

This thesis is an overview of the processes and procedures used in the production of my artistic practice. In my work, I explore notions such as the ambiguity of the photographic image, what constitutes an image or object as photographic, and the unexplored possibilities of the medium through surface and mark making. In addition, I draw inspiration from artists Wolfgang Tillmans, William Henry Fox Talbot, and Marco Breuer as entrance points to my conceptual interests. For viewers, my work generates an internal dialogue about the limits of the photographic medium.

Made available in DSpace on 2016-04-27T17:26:53Z (GMT). No. of bitstreams: 1 Paulo Eduardo Rodrigues Ruiz.pdf: 17241835 bytes, checksum: 3ae3cf02e74bd112c2c13464d3b713ec (MD5) Previous issue date: 2010-11-23 / The aim of this dissertation is to analyze the question of the photographic ambiguity in the 19th century from the theoretical assumption that photography was considered, in its origins, a kind of pencil of nature . This concept was developed by the English researcher and photographer William Henry Fox Talbot, in the work The Pencil of Nature, published between 1844 and 1846. Our discussion is based on the assumption that The Pencil of Nature already presented ambiguities and ambivalences typical of the photographic practice in the 19th century and, to an extent, until today, as regards the technical, scientific, commercial and artistic appeal of an industrial society. We draw examples from the photographic production at the time, using concepts developed by philosophers and theorists of photography such as Martin Heidegger, Walter Benjamin, Roland Barthes, Susan Sontag, Philippe Dubois, André Rouillé and Boris Kossoy, related to some basic notions about the photographic language: the question of technology and photographic verisimilitude, the shift in the perception of reality through photography and the presence of death in the photographic image / O objetivo deste trabalho é refletir a respeito da questão da ambiguidade fotográfica no século XIX a partir do pressuposto teórico de que a fotografia era considerada, em seus primórdios, uma espécie de lápis da natureza . Este conceito foi concebido pelo pesquisador e fotógrafo inglês William Henry Fox Talbot, na obra ThePencilofNature, publicada entre os anos de 1844 e 1846. O fio condutor de nossa discussão parte da hipótese de que ThePencilofNature já apresentava uma série de ambiguidades e ambivalências características da prática fotográfica do século XIX e, em parte, até os dias de hoje, em relação ao apelo técnico-científico, comercial e artístico de uma sociedade industrial. Para tal reflexão, utilizaremos alguns exemplos da produção fotográfica da época, fazendo uso de alguns conceitos de filósofos e de pensadores da fotografia tais como Martin Heidegger, Walter Benjamin, Roland Barthes, Susan Sontag, Philippe Dubois, André Rouillé e Boris Kossoy, relacionados a alguns preceitos básicos sobre a linguagem fotográfica: a questão da técnica e da verossimilhança fotográficas, a transformação da percepção do real por meio da fotografia e a presença da morte no registro fotográfico

Abstract The salt print is an important part of photography, both in its historic value and in the tonal range it can provide. This tonal range is greater than any other photographic printing process available to date attributed to the inherent masking ability of the metallic silver. However the intrinsic production problems have made it a 'forgotten' process. There are five key problems. 1. The difficulties in achieving the potential extensive tonal range. 2. The varying colour of the print. 3. Staining that appears in the print, during and after processing. 4. Instability and longevity of the salt print. 5. Contradictory and inaccurate information in material published on the salt print. Although the emphasis of the research is on exploring and controlling the colour and tonal range, the staining problems and stability of the print are also addressed. The materials used for contact negatives today vary in both capture and output, from analogue film processed in the traditional wet darkroom to a variety of transparent film printed from digital files. Inadequate density and tonal range can affect all types of negatives. To provide sufficient exposure time for the salt prints extended tonal range adjustments to the negative were necessary. These long exposures then converted sufficient silver salts to the image making metallic silver, utilising the intrinsic self-masking process. Ultimately this research has uncovered ways to control colour and tonal range and certain aesthetic qualities of the salt print, while simultaneously resolving some of the conflicts in published information. Accurate and consistent methods of processing eliminate staining, providing some stability to the print. The activities and steps carried out to make a salt print are manual; precise duplication is therefore almost unattainable. Nevertheless, although tests on a densitometer may display numeric differences, visual differences are barely noticeable.