| 摘要 |
PROBLEM TO BE SOLVED: To realize an image-capturing optical system with which it is possible, in spite of relatively wide angle and large diameter, to realize low distortion and obtain excellent image performance excelling in environmental resistance.SOLUTION: The image-capturing optical system has a negative first lens group 1G disposed at the front and a positive second lens group 2G disposed at the rear, both of single focus, across an aperture diaphragm S in between. The first lens group 1G is configured with a first F lens group 1FG comprising positive single lenses and a first R lens group 1RG comprising a negative meniscus lens and a positive lens. The second lens group 2G is configured with a second F lens group 2FG formed by joining positive and negative lenses and a second R lens group 2RG comprising two positive lenses. All of the lenses configuring the image-capturing optical system are spherical glass lenses. |
