Photo: Francisco Moreira da Costa

The daguerreotype, the first photographic process developed by Louis Jacques Mande Daguerre and published by the Academie des Sciences of Paris on August 19, 1839, stunned the world with its ability to reproduce reality by presenting a definition that has never been surpassed by another technique.

Because it is an image formed on the silver, a noble metal, and often treated with a turning point in gold, each a single original copy, the daguerreotype photograph gives the status of jewelry.

The production of a daguerreotype requires concentration, patience, thoroughness, dedication, determination and also great care, since it is made use of hazardous chemicals. It is a long process, composed of several steps: polishing the copper plate, silver plated, awareness, taking the picture, revelation and assembly.

Photo: Francisco Moreira da Costa

With some differences in the materials used and the manner of execution, other processes for capturing and photo printing arose after the invention of the daguerreotype. In a time when color photography did not exist, the color was sought by means of alternative photographic printing processes such as Cyanotype, Salted paper, albumen paper and brown Van Dyke. It is noteworthy that although they are currently called "alternative procedures" at the time were these existing processes, so some prefer to call them "historical processes".

The English astronomer Sir John Herschel was responsible for the invention of these two processes: Cyanotype, print-based salts of iron, invented in 1842, and Van Dyke Brown, based on the first iron-silver process developed by Herschel, the argentotype.

Photo: Camilla Martin

The production of cianótipos of bluish color, requires large negative. Printed by contact, the cianótipos can be obtained either from common negative as drawings or reproductions of transparent or translucent materials. But the result produced by Van Dyke brown printing, which uses negative print size you want, is an image in shades of dark brown. The process was named Van Dyke brown due to the similarity of the color of the print with pigment used by the painter Van Dyck .

Photo: Luis Gustavo Prado

The role albumen is also a process of contact which requires that the negative has the same dimensions of the final copy, and is well mixed. It was at the hands of the Frenchman Louis-Désiré Blanquart-Evrard it was created in 1850. Blanquart extract the clear albumen of chicken eggs and used as a transparent adhesive layer, designed to make the silver halide photosensitive join the base paper. Albumen paper was the most widely used photographic process until the mid 1890s. The production of such paper, not sensitized, set up an important industrial activity in the nineteenth century.

Photo: Luis Gustavo Prado

Near the time of invention of the daguerreotype in 1834, the British William Fox Talbot developed another process based on the light sensitivity of silver chloride. The discovery of Talbot, known as salted paper was widely used from 1840 until the late 1850s, to carry out photographic prints from negatives of paper or glass.

In order to spread the practice of historical processes, of/508 offers, from July 10, the courses: daguerreotype and Alternative Photographic Processes , with guest lecturers Francisco Moreira da Costa and Luis Gustavo Prado, respectively. The courses include a schedule of the Fortnight f/508 Photography (I Love Film), which will be held in August and will honor the photographer Miroslav Tichý .