Objective

An objective comprising:

• a first lens group that has positive refractive power and converts divergent light from an object point to convergent light;
• and
• a second lens group that has negative refractive power and is arranged closer to an image side than the first lens group,
• wherein the first lens group includes a first lens that is a meniscus lens that is situated closest to an object side and has positive refractive power with a concave surface facing the object side,
• the second lens group includes a pair of meniscus lens components having concave surfaces facing each other,
• the second lens group further includes a positive-negative-positive three-piece cemented lens in which positive lenses are arranged on both sides of one negative lens, and
• conditional expressions
• 2.6
• ≤
• φ
• L
• ⁢
• 1
• /
• D
• L
• ⁢
• 1
• ≤
• 16
• (
• 1
• )
• 0.1
• ≤
• ❘
• "\[LeftBracketingBar]"
• R
• 2
• ⁢
• 1
• ⁢
• 2
• ❘
• "\[RightBracketingBar]"
• /
• f
• ≤
• 3.5
• (
• 2
• )
• are satisfied, where φL1 is an outer diameter of the first lens, DL1 is a thickness of the first lens on an optical axis, R212 is a radius of curvature of a surface closest to the image side in a first meniscus lens component, the first meniscus lens component being a meniscus lens component situated on the object side among the pair of meniscus lens components, and f is a focal length of the objective.