Existed between 1892-1910. Light first passed through an almost transparent emulsion layer and was then reflected back by a layer of mercury. Lith film is an extreme form of line film , which produces very high contrast images when used in conjunction with a special lith developer. Local control is a method of controlling the final quality of a print by increasing or decreasing the exposure given to localized areas of the print by selective masking. Long focus describes a lens in which the focal length is much greater than the diagonal of the film format with which it is used.
Low key is a photograph in which tones are predominantly dark and there are few highlights.
Lumen is a unit of light intensity falling onto a surface. Lumen second is a unit to measure the total light output of a photographic source. Luminance is the measurable amount of light which is emitted by or reflected from a source. Luminance meter is an alternate term for exposure meter . Luminescence is the visible light produced from a surface submitted to invisible radiation such as UV, X rays and son on.