| 摘要 |
A wide angle lens whose field angle exceeds 180 degrees includes a front group, a diaphragm, and a rear group arranged in this order from an object side toward an image side. The front group includes a first lens (negative meniscus lens) whose convex surface faces the object side, a second lens (negative lens), and a third lens (positive lens) that are arranged in this order from the object side toward the image side. The rear group includes a fourth lens (positive lens), a fifth lens (negative lens), and a sixth lens (positive lens) that are arranged in this order from a diaphragm side toward the image side. Accordingly, an imaging system including six separate lenses is formed. The third lens is made of a material having an Abbe numberνdL3 satisfyingνdL3<21. The fifth lens is made of a material having an Abbe numberνdL5 satisfyingνdL5<21.
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