| 摘要 |
An optical system according to an embodiment includes a first lens, a second lens, and a third lens arranged in order from an object to an image. The optical system satisfies the following formula 1 and formula 2: [Formula 1] 0.6 < D2/Sag 2 where D2 is a radius of investigation of the side of the first lens and Sag 2 is a Sag value of the side of the first lens; and [Formula 2] 0.5 < D3/Sag 3 where D3 is a radius of investigation of the side of the second lens and Sag 3 is a Sag value of the side of the second lens. |
