1. Field of the Invention
The present invention relates to a negative leading type two-lens-group zoom lens system and in particular to a fast super wide-angle zoom lens system having a wide angle of view.
2. Related Background Art
Although a lot of so-called wide-angle zoom lens systems have been proposed, there have been proposed very small number of wide-angle zoom lens systems covering entire super wide-angle range with a maximum angle of view of 110 degrees or more, and among them extremely small number of super wide-angle lens system having a fast aperture ratio with an f-number of about 2.8 have been proposed in, for example, Japanese Patent Application Laid-Open No. 2001-166206.
Recently, with increasing digitization of a camera, further higher optical performance has been necessary for even a wide-angle zoom lens system.
However, the zoom lens system disclosed in Japanese Patent Application Laid-Open No. 2001-166206 has a large diameter aspherical lens as a front lens. Since such an aspherical lens is difficult to be manufactured, there has been a problem that the zoom lens system itself becomes difficult to be manufactured.
USPTO Backgrounds
USPTO Backgrounds