Super wide angle lens system using an aspherical lens

摘要

A retrofocus type super wide angle lens system includes a front lens group of negative power and a rear lens group of positive power, arranged in this order from the object side. The front lens group consists of a negative meniscus first lens element with a convex surface facing the object side and a second lens element having at least one aspherical surface, arranged in this order from the object side. The aspherical second lens element is shaped such that it forms a biconcave lens in the vicinity of the optical axis and forms a negative meniscus lens with a convex surface located on the object side at a peripheral portion thereof.