Early Work In Photography
A Text-book For Beginners

GLOSSARY OF TERMS. The following list includes the principal photographic terms used in the first chapters of EARLY Work. Actinic.—By “actinie light” in photography is meant the active rays capable of affecting a photographic dry plate; white light, or white light transmitted through a blue or violet glass, has actinic power, but red light has not. Red light is inactive, or " non-actinic.” BACK OF NEGATIVE.—When one speaks of the “back” of a negative, the glass side is always meant. The film side (on which the image is formed) is called the “front,” or film side. Emulsion.—A photographic emulsion is a thick, semi-fluid mass composed of gelatine or collodion, containing silver com- pounds in suspension. The emulsion, when spread on glass and dried, forms the sensitive film of the modern dry plates. Face Side.—The film side of a negative is sometimes called the “face,” or film side, and sometimes the “front,” to distin- guish it from tlie back or glass side. Front of Negative..—See FACE SIDE. Graduate.—A graduated glass used for measuring liquids. Light-tight.—A common term in photography, used to indicate anything through which light cannot leak. Thus, if the chinks around the door of a dark room admit stray white light, it is not light-tight; but by pasting black paper over the crevices the room becomes light-tight. The same defi- nition applies indiscriminately to cameras and plate boxes. Non-actinic.—Rays of light incapable of affecting a photographic plate are usually termed “non-actinic” or inactive. Red and yellow light are more or less non-actinic, lienee their use for illuminating the dark room. Vone.-The general definition of this word in photography is “color.” The “tone” of a silver print is formed by the deposition of violet gold or platinum black. I he act of depositing precious metals upon the silver image is com- monly called "toning." Trim.—To " trim ” a print is to cut the edges true by means of a knife and a sheet of glass; an untrimmed print is one with its edges rough and unfinished. All prints must be carefully trimmed before they are mounted upon cardboard.