Dating old english photographs
Refinements of the gelatin process have remained the primary black-and-white photographic process to this day, differing primarily in the sensitivity of the emulsion and the support material used, which was originally glass, then a variety of flexible plastic films, along with various types of paper for the final prints.
Color photography is almost as old as black-and-white, with early experiments including John Herschel's Anthotype prints in 1842, the pioneering work of Louis Ducos du Hauron in the 1860s, and the Lippmann process unveiled in 1891, but for many years color photography remained little more than a laboratory curiosity.
The process and practice of creating such images is called photography.
The word photograph was coined in 1839 by Sir John Herschel and is based on the Greek φῶς (phos), meaning "light," and γραφή (graphê), meaning "drawing, writing," together meaning "drawing with light." The first permanent photograph, a contact-exposed copy of an engraving, was made in 1822 using the bitumen-based "heliography" process developed by Nicéphore Niépce.
The first photographs of a real-world scene, made using a camera obscura, followed a few years later, but Niépce's process was not sensitive enough to be practical for that application: a camera exposure lasting for hours or days was required.
In 1829 Niépce entered into a partnership with Louis Daguerre and the two collaborated to work out a similar but more sensitive and otherwise improved process.
Since the 1990s, panoramic photos have been available on the Advanced Photo System (APS) film.
The mid-1930s saw the introduction of Kodachrome and Agfacolor Neu, the first easy-to-use color films of the modern multi-layer chromogenic type.Before recent advances in digital photography, transparencies were widely used by professionals because of their sharpness and accuracy of color rendition.Most photographs published in magazines were taken on color transparency film.After Niépce's death in 1833 Daguerre concentrated on silver halide-based alternatives.He exposed a silver-plated copper sheet to iodine vapor, creating a layer of light-sensitive silver iodide; exposed it in the camera for a few minutes; developed the resulting invisible latent image to visibility with mercury fumes; then bathed the plate in a hot salt solution to remove the remaining silver iodide, making the results light-fast.