Retrofocus lens, an imaging apparatus, and the focusing method of the retrofocus lens

摘要

PPROBLEM TO BE SOLVED: To provide a retrofocus lens which reduces aberration fluctuation in focusing on a near subject of a high photographing magnification, and reduces ghost and flare. PSOLUTION: The retrofocus lens RL comprises a first lens group G1 having negative refracting power, a second lens group G2 having negative refracting power, and a third lens group G3 having positive refracting power. The first lens group G1, the second lens group G2, the third lens group G3 move to a subject side along an optical axis so as to reduce an interval between the second lens group G2 and the third lens group G3 while increasing an interval between the first lens group G1 and the second lens group G2. An antireflective coating is provided on at least one surface out of optical surfaces of the first lens group G1 and the third lens group G3, and the antireflective coating is formed to include at least one layer which is formed by wet process. PCOPYRIGHT: (C)2009,JPO&INPIT