Cyanotype

Cyanotype technique using light sensitivity of iron salts. As the creator of cyanotype considered Willam John Frederick Herschel (1792-1871). Herschel is best known for the discovery in 1819 in the capacity of sodium thiosulfate to dissolve the silver chloride. This discovery (1839 year), in conjunction with kalotypią William Henry Fox Talbot (1800-1877), the possibility of capturing images. That same year, Herschel also formulated the terms used today ie: photography, negative and positive. In their experiments searching for cheaper methods of reproduction - unfortunately no photos, but notes. The method, invented by Herschel - Richard T. Rosenthal called cyjanotypią.Anna Atkins (1799-1871), botanist, one of the first female photographers, in 1841 she met Talbot (creator kalotypii) friend of her father. Under the influence of an interest in photography Talbot. For his work as an elected Cyanotype affordable, easy and inexpensive to produce. Released in 1843, the first volume of books Fri British algae: Cyanotype Impressions. " This was done in the whole book Cyanotype (including text and illustrations). Ahead of this book Talbot Fri "The Pencil of Nature" (1844). His works were performed piling leaves and flowers directly on paper. Issued a total of 12 parts, 424 photos illustrating them in the cyanotype technique. Rediscovered in 1966 when it appeared on the auction of its książka.Francuz Henri Jean-Louis le Secq (1818 -1882), he used this method in the early 50s of the XIX century. In 1852 he received from the Commission des Monuments Historiqes commissioned the preparation of documentation in the cathedrals of Rheims and Chartres. Partially done work in cyanotype. This method also used the Hyppolite Bayard (1801-1887), Dr. Peter Henry Emerson (1856-1936) and of course the same Talbot. Since 1880, cyanotype paper was produced in large quantities. Used it often - even in the 90s of the twentieth century - the architects and engineers to make copies of technical drawings. Inexpensive method of exposing the contact exposure on paper soaked in salt solution of potassium ferrocyanide and iron oxide. Under the influence of light reaction of salt iron oxide which darkens giving the Prussian blue. Areas covered are white. Prints are called Blueprint (blue print). The resulting images are often contrasting and probably not suitable for halftone photographs. Finished prints are apparently not very stable, but until today pictures from 1843.