| 摘要 |
Provided is a small-sized wide-angle optical system which can match the high pixels of an imaging element and can have a better optical performance and an ultra-wide field angle. The wide-angle optical system is constituted of a front group (11), a diaphragm (12) and a rear group (13) sequentially from an object side to an image side. The front group (11) is constituted, sequentially from the object side to the image side, to include a first lens (111) having a negative optical power, a second lens (112) having a negative optical power, and a third lens (113) having a positive optical power. The rear group (13) is constituted, sequentially from the object side to the image side, to include a fourth lens (131) having a positive optical power, and a fifth lens (132) having a negative optical power. The paired lenses (113 and 131) across the diaphragm (12) have convex faces on the individual sides far from the diaphragm. |
