| 摘要 |
This optical system comprises, in order along the optical axis from the object side, a first lens that has a negative refractive power, a second lens that has a negative refractive power, a third lens that has a positive refractive power, and a lens located on the image side of the third lens. When focusing from an object at infinity to an object at close range, the third lens moves along the optical axis. This makes it possible for the optical system to perform focusing using a small number of lenses and to exhibit high image-forming performance. |
