Lens optical system and imaging apparatus

Abstract

The present technology relates to a lens optical system and an imaging apparatus that can realize both good imaging quality and a small F-number in a small size and a wide angle. The lens optical system includes a first lens group having negative refractive power and a second lens group having positive refractive power in order from the object side toward the image side. The first lens group includes a first lens having negative refractive power. The second lens group includes, in order from the object side to the image side, a second lens having positive refractive power, a third lens having negative refractive power, a fourth lens having positive or negative refractive power, a fifth lens having positive refractive power, and a sixth lens having negative refractive power. When a focal length of the entire lens optical system is f and a focal length of the second lens group is fa2, the lens optical system satisfies a condition of 1≤fa2/f≤2. The present technology can be applied to, for example, a lens optical system and the like.

Dependencies are inferred from the claim text.