Origin of The Process
In 1851, Frederick Scott Archer introduced a wet plate process, sometimes referred to as the collodion process after the carrier material used. The process is simple: a bromide, iodide, or chloride is dissolved in collodion (a solution of pyroxylin in alcohol and ether). This mixture is poured on a cleaned glass plate, which is allowed to sit until the coating gels but is still moist. The plate is then placed in a silver nitrate solution, which converts the iodide, bromide, or chloride to silver iodide, bromide or chloride. Once the reaction is complete, the plate is removed from the silver nitrate solution and exposed in a camera while still wet. The plate loses sensitivity as it dries, requiring it to be coated and sensitized immediately before use. It must also be developed while still moist, using a solution of iron sulfate, acetic acid and alcohol in water.
The sensitivity of silver halides to light is the underlying principle behind most types of 19th century photographic processes (Daguerreotypes, Ambrotypes, Calotypes that use paper negatives, and wet and dry plates) as well as modern 20th century photographic film processes.
Read more about this topic: Collodion Process
Famous quotes containing the words origin of the, origin of, origin and/or process:
“In the woods in a winter afternoon one will see as readily the origin of the stained glass window, with which Gothic cathedrals are adorned, in the colors of the western sky seen through the bare and crossing branches of the forest.”
—Ralph Waldo Emerson (1803–1882)
“There are certain books in the world which every searcher for truth must know: the Bible, the Critique of Pure Reason, the Origin of Species, and Karl Marx’s Capital.”
—W.E.B. (William Edward Burghardt)
“The real, then, is that which, sooner or later, information and reasoning would finally result in, and which is therefore independent of the vagaries of me and you. Thus, the very origin of the conception of reality shows that this conception essentially involves the notion of a COMMUNITY, without definite limits, and capable of a definite increase of knowledge.”
—Charles Sanders Peirce (1839–1914)
“Healthy parenting is nothing if not a process of empowerment. As we help to raise our children’s self-esteem, we also increase their personal power. When we encourage them to be confident, self-reliant, self-directed, and responsible individuals, we are giving them power.”
—Louise Hart (20th century)