CALOTYPE Calotype also called talbotype was developed in 1840 by William Henry Fox Talbot. Calotype means beautiful impression and is an early photographic process using paper coated with silver iodide. This process was a refinement of the technique photogenic drawings. In this report I will do more research about calotype and the person that invented the process. I will also write about how Talbot’s work and technique is important for photography today.
William Henry Fox Talbot
William Henry Fox Talbot was born 11 February 1800 in Melbury, Dorset. He went to Cambridge University in 1817 was an English scientist, inventor and photography pioneer. The process he discovered formed the basis for both photography and photographic printing plates. He married his wife Constance in 1832 and she also participated in image making with Talbot. This makes her the first known woman photographer.
Talbot enjoy painting but his lack of success made him dream about a new machine with light-sensitive paper that would make the sketches for him automatically. After a trip to Lake Como in Italy he returned to England and began working on this project. Fox Talbot developed the three primary elements of photography: developing, fixing and printing. This process required extremely long exposure time. By accident, he discovered that there was an image after a very short exposure. He couldn’t see it, but he found out that he could develop a useful negative with a chemical solution. The chemical solution removed the light-sensitive silver and enabled the picture to be viewed in bright light. He then realized that he could repeat the process of printing from the negative. His process could make any numbers of positive prints, unlike the Daguerreotypes. Talbot called this the calotype and patented the process in 1841. He was rewarded with a medal from the Royal Society for his work. He died on 11 September 1877. The Pencil of Nature by Henry William Fox Talbot was the first photographically illustrated book to be commercially published. Calotype
Calotype means beautiful impression and it is the first negative-positive photographic process. Calotype was a refinement of the process of photogenic drawing and was invented by Fox Talbot in September 1840. Talbot was the first to apply to a paper-based process and to a negative-positive process, which have dominated non- electronic Calotype camera photography up to the present.
The attraction of the calotype process was that you could transform the paper into an actual image after the paper had been removed from the camera. The process allowed much shorter exposures that photogenic drawing and this made portraits possible. The exposure time was around 1 to 3 minutes for a calotype and for the earlier process it required an hour.
The negative calotype process: 1. Rather than the glass or film Talbot used high quality writing paper. The first stage was to prepare what he called iodized paper. The paper was washed over with a solution of silver nitrate and dried by gentle heat. When it was nearly dry the paper got soaked in a solution of potassium iodide for two or three minutes, rinsed and dried again. 2. Before taking a photograph a fresh solution of gallo-nitrate of silver was mixed up. Then under weak candlelight the iodized paper was coated with this solution and after thirty seconds dipped in water. It was then partially dried in the dark. The calotype paper could be employed dry, but was more sensitive when moist.
3. Under neat-total darkness the sensitive calotype paper was loaded in the camera. It was exposed to the scene, usually for a time closer to a minute. After taking the paper out of the camera you can’t see the image. An invisible latent image was formed by the action of lights. A fresh solution of gallo-nitrate of silver is washed over the sheet of paper in a darkened room. It developed a visible image, usually within a few seconds. When the operator judged that the development had proceeded far enough, the paper was washed over with a fixing liguid. Washing and drying completed the process.
Calotype paper could be used to make positive prints from calotype negatives, but Talbot normally used salted paper for that purpose. It was simpler, more attractive and less expensive.
Calotype negative and salted paper print by William Henry Fox Talbot. The picture is called An oak tree in winter, from 1842-43. Photography today Tablot invention was important for photography today because this was the first step to paper-based images. It was also the first negative-positive process which have dominated non-electronic photography until today. Negatives made it possible to make more than one image of the same photo. Calotype process allowed shorter exposure and made it possible to make portraits. So all this steps was importent for the development of the history of photography and what it is today.