1. Technical Field
The present invention relates to a super-wide-angle lens and an imaging apparatus, and more particularly to a super-wide-angle lens which can be used for a digital camera, a broadcasting camera, a movie camera, and the like; and an imaging apparatus including the super-wide-angle lens.
2. Description of the Related Art
In recent years, there is great demand for cameras in the above fields to have a small F-number which enables photography in dark places and to have high performance which can be compatible with recent high-definition imaging elements. Moreover, for example, some movie cameras and the like are provided with a mechanism for driving power focus of a focusing group (a lens group which moves while focusing) such as an autofocus mechanism and the like. As there are many opportunities to photograph subjects which are moving, there is demand for a lightweight focusing group and suppression of fluctuations in aberrations and fluctuations in the angle of view in order to have superior responsiveness to focusing when the distance to a subject is changed. Taking these circumstances into consideration, the inner focus lens system is often adopted. Examples of the inner focus lens system include the lens systems disclosed in Japanese Unexamined Patent Publication No. 2011-186269 and Japanese Unexamined Patent Publication No. 2011-028009.
In contrast, many wide angle type lenses for movie cameras are conventionally of the fixed focus type from the viewpoint of optical performance, and are often used by changing a plurality of lenses according to the intended application. For example, the lens disclosed in Japanese Unexamined Patent Publication No. 2000-056217 of a retrofocus type in which a negative first lens group, a positive second lens group, and a positive third lens group are arranged in this order from the object side is known as a wide angle lens.