| 摘要 |
<p>[Problem] To realize superior optical performance in a wide-angle lens while developing a lighter weight lens group that focuses with a smaller F number and a wider angle. [Solution] A positive first lens group (G1), a second lens group (G2) that is composed of no more than two lenses and moves when focusing, and a third lens group (G3) provided with at least one positive lens are provided in order from the object side. The first lens group (G1) is provided with, in order from the object side, at least a positive meniscus lens (L1) having the convex surface directed toward the object side, a negative meniscus lens (L2) having the convex surface directed toward the object side, (L3) directed toward the concave surface of the smaller absolute value of the radius of curvature on the image side, a negative lens (L4), a doublet lens composed of a positive lens and a negative lens placed further to the image side than the negative lens (L4), and an aperture stop (St) provided close to the image side of the doublet lens; and satisfies the specified condition equations.</p> |
