By Dr. Robert Leggat

First, the name. We owe the name "Photography" to Sir John Herschel , who first used the term in 1839, the year the photographic process became public. The word is derived from the Greek words for light and writing.

There are two distinct scientific processes that combine to make photography possible. It is somewhat surprising that photography was not invented earlier than the 1830s, because these processes had been known for quite some time. It was not until the two distinct scientific processes had been put together that photography came into being.

The first of these processes was optical. The Camera Obscura (dark room) had been in existence for at least four hundred years. There is a drawing, dated 1519, of a Camera Obscura by Leonardo da Vinci; about this same period its use as an aid to drawing was being advocated.

The second process was chemical. For hundreds of years before photography was invented, people had been aware, for example, that some colours are bleached in the sun, but they had made little distinction between heat, air and light.

• In the sixteen hundreds Robert Boyle, a founder of the Royal Society, had reported that silver chloride turned dark under exposure, but he appeared to believe that it was caused by exposure to the air, rather than to light.
• Angelo Sala, in the early seventeenth century, noticed that powdered nitrate of silver is blackened by the sun.
• In 1727 Johann Heinrich Schulze discovered that certain liquids change colour when exposed to light.
• At the beginning of the nineteenth century Thomas Wedgwood was conducting experiments; he had successfully captured images, but his silhouettes could not survive, as there was no known method of making the image permanent.

The first successful picture was produced in June/July 1827 by Niépce, using material that hardened on exposure to light. This picture required an exposure of eight hours.

On 4 January 1829 Niépce agreed to go into partnership with Louis Daguerre. Niépce died only four years later, but Daguerre continued to experiment. Soon he had discovered a way of developing photographic plates, a process which greatly reduced the exposure time from eight hours down to half an hour. He also discovered that an image could be made permanent by immersing it in salt.

Following a report on this invention by Paul Delaroche, a leading scholar of the day, the French government bought the rights to it in July 1839. Details of the process were made public on 19 August 1839, and Daguerre named it the Daguerreotype.

The announcement that the Daguerreotype "requires no knowledge of drawing...." and that "anyone may succeed.... and perform as well as the author of the invention" was greeted with enormous interest, and "Daguerreomania" became a craze overnight. An interesting account of these days is given by a writer called Gaudin, who was present the day that the announcement was made.

However, not all people welcomed this exciting invention; some pundits viewed in quite sinister terms. A newspaper report in the Leipzig City Advertiser stated:

"The wish to capture evanescent reflections is not only impossible... but the mere desire alone, the will to do so, is blasphemy. God created man in His own image, and no man- made machine may fix the image of God. Is it possible that God should have abandoned His eternal principles, and allowed a Frenchman... to give to the world an invention of the Devil?"

At that time some artists saw in photography a threat to their livelihood, and some even prophesied that painting would cease to exist.

The Daguerreotype process, though good, was expensive, and each picture was a once-only affair. That, to many, would not have been regarded as a disadvantage; it meant that the owner of the portrait could be certain that he had a piece of art that could not be duplicated. If however two copies were required, the only way of coping with this was to use two cameras side by side. There was, therefore, a growing need for a means of copying pictures which daguerreotypes could never satisfy.

Different, and in a sense a rival to the Daguerreotype, was the Calotype invented by William Henry Fox Talbot, which was to provide the answer to that problem. His paper to the Royal Society of London, dated 31 January 1839, actually precedes the paper by Daguerre; it was entitled "Some account of the Art of Photogenic drawing, or the process by which natural objects may be made to delineate themselves without the aid of the artist's pencil." He wrote:

"How charming it would be if it were possible to cause these natural images to imprint themselves durably and remain fixed on the paper!" The earliest paper negative we know of was produced in August 1835; it depicts the now famous window at Lacock Abbey, his home. The negative is small (1" square), and poor in quality, compared with the striking images produced by the Daguerreotype process. By 1840, however, Talbot had made some significant improvements, and by 1844 he was able to bring out a photographically illustrated book entitled "The Pencil of nature."

Compared with Daguerreotypes the quality of the early Calotypes was somewhat inferior. However, the great advantage of Talbot's method was that an unlimited number of positive prints could be made. In fact, today's photography is based on the same principle, whereas by comparison the Daguerreotype, for all its quality, was a blind alley.

The mushrooming of photographic establishments reflects photography's growing popularity; from a mere handful in the mid 1840s the number had grown to 66 in 1855, and to 147 two years later. In London, a favourite venue was Regent Street where, in the peak in the mid 'sixties there were no less than forty-two photographic establishments! In America the growth was just as dramatic: in 1850 there were 77 photographic galleries in New York alone. The demand for photographs was such that Charles Baudelaire (1826-1867), a well known poet of the period and a critic of the medium, commented:

"our squalid society has rushed, Narcissus to a man, to gloat at its trivial image on a scrap of metal."

Talbot's photography was on paper, and inevitably the imperfections of the paper were printed alongside with the image, when a positive was made. Several experimented with glass as a basis for negatives, but the problem was to make the silver solution stick to the shiny surface of the glass. In 1848 a cousin of Nicephore Niépce, Abel Niépce de Saint-Victor, perfected a process of coating a glass plate with white of egg sensitised with potassium iodide, and washed with an acid solution of silver nitrate. This new ( albumen ) process made for very fine detail and much higher quality. However, it was very slow, hence the fact that photographs produced on this substance were architecture and landscapes; portraiture was simply not possible.

Progress in this new art was slow in England, compared with other countries. Both Daguerre and Fox Talbot were partly responsible, the former for having rather slyly placed a patent on his invention whilst the French government had made it freely available to the world, the latter for his law-suits in connection with his patents.

In 1851 a new era in photography was introduced by Frederick Scott Archer , who introduced the Collodion process. This process was much faster than conventional methods, reducing exposure times to two or three seconds, thus opening up new horizons in photography.

Prices for daguerreotypes varied, but in general would cost about a guinea (£1.05), which would be the weekly wage for many workers. The collodion process, however, was much cheaper; prints could be made for as little as one shilling (5p).

A further impetus was given to photography for the masses by the introduction of carte-de-visite photographs by Andre Disdéri. This developed into a mania, though it was relatively short-lived.

The collodion process required that the coating, exposure and development of the image should be done whilst the plate was still wet. Another process developed by Archer was named the Ambrotype, which was a direct positive.

The wet collodion process, though in its time a great step forward, required a considerable amount of equipment on location. There were various attempts to preserve exposed plates in wet collodion, for development at a more convenient time and place, but these preservatives lessened the sensitivity of the material. It was clear, then, that a dry method was required.

The next major step forward came in 1871, when Dr. Richard Maddox discovered a way of using Gelatin (which had been discovered only a few years before) instead of glass as a basis for the photographic plate. This led to the development of the dry plate process. Dry plates could be developed much more quickly than with any previous technique. Initially it was very insensitive compared with existing processes, but it was refined to the extent that the idea of factory-made photographic material was now becoming possible.

The introduction of the dry-plate process marked a turning point. No longer did one need the cumbersome wet-plates, no longer was a darkroom tent needed. One was very near the day that pictures could be taken without the photographer needing any specialised knowledge.

Celluloid had been invented in the early eighteen-sixties, and John Carbutt persuaded a manufacturer to produce very thin celluloid as a backing for sensitive material. George Eastman is particularly remembered for introducing flexible film in 1884. Four years later he introduced the box camera, and photography could now reach a much greater number of people.

Other names of significance include Herman Vogel, who developed a means whereby film could become sensitive to green light, and Eadweard Muybridge who paved the way for motion picture photography.

Popular in the Victorian times was stereoscopic photography, which reproduced images in three dimensions. It is a process whose popularity waxed and waned - as it does now - reaching its heights in the mid-Victorian era.