PHOTOGRAPHY 150 : Images from the First Generation
A small exhibition of treasures from the Museum's celebrated collection of early photographs (1839 - 1859), to mark the 150th anniversary of the invention
Case 2 PHOTOGENIC DRAWINGS
The display case contains a selection from the Museum's collection of photogenic drawings, one of the two independently-invented photographic processes which were announced to the public 150 years ago, in January 1839. Sir John Herschel's experimental material dominates the display, though restricted to less than fifty out of over 500 pieces. These represent his important hypo fixing experiments, his trials with colouring juices from flowers, the invention of the cyanotype or blueprint, and other experimental processes for fixing, developing, and sensitising. They include the Museum's earliest dated photograph, a contact image made on February 7, 1839; and its earliest dated camera image, taken on November 30, 1839. Many more of the Herschel items date from a full 150 years ago, as do the photographs by Robert Hunt, using his own direct-positive photogenic drawing process, and those by W. H. Fox Talbot, the inventor himself, one of them dated March 1839. Also exhibited are the photogenic drawing by George Dollond, rare evidence of the elderly optician's involvement in the early days of photography; and the first photographically- produced book, Anna Atkins's inspired application of the cyanotype, issued in 1843 (the youngest item in the display!).
HISTORY The photogenic drawing was invented by William Henry Fox Talbot (1800-1877), a gentleman scientist whose interests included optics, chemistry, botany, and art. His frustration at trying to draw with the camera lucida led him to explore the idea of making images chemically print themselves on paper. He soon learned of the experiments to this end which Thomas Wedgwood had conducted from at least 1799, published by Davy in 1802. Wedgwood (who died in 1805) had succeeded in making contact images but not in preserving them. Talbot achieved almost immediate success with contact printing in 1834, and soon afterwards with images made in tiny box cameras which originated as substitutes for the camera obscura. A camera negative survives from as early as August 1835. During the next few years his interest in these experiments waned, until Daguerre's discovery, announced on January 7, 1839, jolted him into reviving and making public his own. He first did so at the Royal Institution, London, on January 25, when specimens of his photogenic drawings were exhibited by arrangement with the chemist Faraday. On the same day he wrote of his invention to Herschel. On January 31 he read a paper to the Royal Society of London, which was published during February; and on February 21 he revealed the full details of the process. By April the print dealer Ackermann was selling an outfit of chemicals and papers for photogenic drawing, along with a pamphlet of instructions.
Herschel in England and Bayard in France were the most important of many who launched into photographic experiments at this time. Commencing within a day or so of receiving Talbot's letter of January 25, 1839, Herschel explored a wide range of materials and processes [see illustrations]. Some, notably the fixative hypo, resulted immediately in significant improvements to Talbot's invention. His initial results were reported to the Royal Society on March 14, though his experiments continued for four years. The photogenic drawing remained essentially experimental; and the ultimate result of such experiments was Talbot's own invention of the calotype, which superseded it in 1841.
SCIENCE The photogenic drawing is supported on best quality writing or drawing paper, generally that manufactured by Whatman. The piece of paper was immersed in a weak solution of sodium chloride (common salt), then dried. One side was brushed with a solution of silver nitrate, making it light-sensitive. Before use the paper was washed again in a salt solution, this time strong. It was exposed in sunlight, usually in contact with an object such as lace, a leaf, or an engraving, sometimes in the microscope, and sometimes, less successfully, in the camera obscura or the simple box camera (a form of which was marketed for photogenic drawings in June 1839). During exposure the image 'printed out', that is, the exposure continued for as long as it took the image to appear. The paper was then immersed in a strong solution of salt, which neutralised remaining light-sensitive agents. This, or potassium idodide, was Talbot's method of fixing; but Herschel's 'hypo' (sodium thiosulphate) was much more efficient, dissolving away all the remaining silver nitrate. It became the standard fixer for all silver processes. Thorough washing in water was needed after fixing, though this was not always realised by the early practitioners. The negative photogenic drawing, a contact image of lace for instance, was often adequate. But if it was sufficiently translucent the negative could be re-photographed by exactly the same method, in other words, contact printed as a positive. Translucency was sometimes enhanced by applying varnish, wax or oil.
Herschel and other experimenters quickly developed improvements and variations of Talbot's invention, and explored more widely the chemistry of photosensitive materials. The main variants of the photogenic drawing which are represented in this display are summarised below.
Hunt's Direct Positive Robert Hunt, who also began experimenting in 1839, invented and marketed a process which, like that of the French pioneer Bayard, achieved a positive image without a negative stage. He used exposed (blackened) silver nitrate paper re-sensitised with potassium iodide or other metal salts. The black paper was bleached by the light, and the resulting image fixed (so Hunt's instructions claim) by soaking in water.
Phytotype Herschel's 'vegetable photographs' of 1841, to which he though of giving the name 'phytotype', resulted from his exploration of photosensitive botanical materials. Colouring juices extracted from flower petals were used as sensitising agents, or rather as dyes which the light (through a contact object) bleached, forming a direct-positive image. The juices sometimes dyed the paper quite a different colour from the petals, crimson poppy for instance producing a slate blue (and forming the most successful images). The process was very slow and its results impermanent, yet amazingly after 150 years a number of specimens survive.
Cyanotype Exploring the photographic potential of metals other than silver, Herschel invented the 'cyanotype' or 'blueprint' in 1842. It employed iron salts (ferric ammonium citrate and potassium ferricyanide) which produce Prussian blue under the action of light. It was a simple process to use, and required only water as a fixative. Experimental variants included a direct positive where a surprising two-colour, green and blue effect resulted. The cyanotype was the only first-generation photographic technique to be usefully employed into modern times, most familiarly by engineers and architects.
Chrysotype Invented at the same time as the cyanotype, the 'chrysotype' formed a latent image from light-sensitive iron salts, which was developed with gold chloride solution, producing a purple image made of metallic gold.
ART The photogenic drawing had little chance to develop an artistic presence as it was so quickly superseded, and the potential that Talbot talked of in his paper to the Royal Society was to be realised largely by the calotype. Its camera images were far inferior to the daguerreotype's. Although Herschel photographed the superstructure his father's telescope before it was dismantled [see illustration], he still made camera lucida drawings (by hand) in order to obtain clear records of it. To many it seemed that contact-copying prints and drawings might be the ultimate vocation of the photogenic drawing process. In fact its special talent was to make contact images of delicately translucent objects such as leaves and lace. At the time, these novel representations had much appeal. They are the ancestors of the 'photograms' once popular with avant-garde photographers. More immediately they became annexed to the tradition of botanical illustration, the cyanotype proving particularly suitable for the purpose.
Herschel's fascination with the achievement of colours by photochemical means belonged to a wider interest in colour shared by artists and scientists, and shows that the pioneers of photography did not consider themselves enslaved to black-and white or sepia. He tried to invent true colour photography; and when this became a reality over fifty years later, his cyanotype was often used as the basis (the blue layer) of the early three-colour prints and transparencies. Herschel also, in a subtle way, influenced the evolution of photography's picturesque style. His choice of engravings to use in his experiments mediated between the genres of Romantic pictorialism and the new visual world which photography was to become. The engravings were taken from illustrated part-works that were a fashion of the early and mid nineteenth century, on themes of travel, history, and literature. And although only an experimenter himself, several artistic photographers acknowledged Herschel as a mentor and sought his critical approval, including Regnault and Julia Margaret Cameron.
[From the exhibition booklet Photography 150: Images from the First Generation (Oxford: Museum of the History of Science, 1989)]