Macro photography is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life-size. By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life-size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life-size. The ratio of the subject size on the film plane to the actual subject size is known as the reproduction ratio.