Patent ID: 6359739
Filing Date: 2002-03-19
Classification: G02B

Abstract:
A macro lens system comprising a positive first lens group, a negative second lens group, a positive third lens group, and a negative fourth lens group, in this order from an object;wherein upon focusing from an infinite photographing distance to the closest photographing distance, said second lens group moves towards an image, said third lens group moves toward said object, and said fourth lens group remains stationary; and wherein said macro lens system satisfies the following condition: 3.7fÃ—m/&Dgr;X3|<9.9 â€ƒwherein f designates the focal length of the entire lens system at an infinite photographing distance; m designates the transverse magnification at the closest photographing distance; and &Dgr;X3 designates the traveling distance of said third lens group from said infinite photographing distance to the closest photographing distance.