Photography

Photography literally means 'painting with light' (from the Greek photos, light, and grapho, to describe, write or draw). Photography is the art and science of capturing an image on a light sensitive material. Photography is usually done with a camera using visible light, but other forms of photography include photograms, microphotography, infra red, ultra violet and x-ray photography and astronomical photography using various kinds of telescopes.

The first photograph

Joseph Nicéphore Niépce is generally credited as the first person to successfully combine the camera obscura with a 'fixable' light sensitive material to produce the first 'heliograph' in 1826. He was initially interested in lithography, working with his son acting as draftsman. When his son was called away to war his own poor drawing skills forced him to experiment with other methods of obtaining an image. He began experimenting with glass and copper plates, using silver chloride varnishes amongst other methods, but like others before him he was unable to 'fix', or make permanent, the image. His first success came with the use of bitumen of Judea, a refined asphaltum mixed with oil of lavender and turpentine, that was used as an etching resist. He found that if he made a paper print (etching) transparent by soaking it in oil and laying on a prepared glass plate, then exposing that to the sun, areas exposed to light hardened and bleached a little (to a grey color). Those areas under the black portions of the image remained soft and could be washed away with a mixture of turpentine and oil of lavender. He was able to create the first photo etchings this way with copper plates, which could then be etched in an acid bath to produce a printing plate. After buying a professional camera obscura he was able to use this process on pewter plates prepared with bitumen of Judea placed in the back of the camera to produce the first "heliograph from nature". This image took 8 hours to expose, and has to be viewed at an angle, but it is the first permanent photograph ever produced.