stop number

Found in Anh - Anh (Wordnet)

Definition Noun : The ratio of the focal length to the diameter of a (camera) lens system : This is a technical term in optics and photography that quantifies the light-gathering ability of a lens. A lower number indicates a larger aperture (more light entering), while a higher number indicates a smaller aperture (less light entering). Usage The term "stop number" is used almost exclusively in...