Photographic modified retro-focus type wide angle lens i.e. reverse telephoto-type lens, has rear group formed of lens groups, where distance between lens groups is reduced during focusing of object from infinity to short-range

摘要

The lens has a positive refractive power rear group (Gh1) displaceable along an optical axis, and an aperture stopper (BL) arranged between the rear group and another positive refractive power rear group (Gh2). The former group is formed of two positive refractive power lens groups (G2, G3) that are displaced towards the latter group for focusing an object from infinity to a short-range, where a distance between the lens groups is reduced during focusing from the infinity to the short-range. A negative refractive power front lens group (G1) comprises four lenses. The four lenses are designed as a negative refractive power aspherical lens (L1), a negative refractive power lens (L2), a negative refractive power bi-concave lens (L3) and a positive refractive power bi-convex lens (L4), respectively.