| 摘要 |
PROBLEM TO BE SOLVED: To provide an attachment optical system for obtaining satisfactory optical performance within various sizes of photographic ranges in the case of reimaging a primary image formed on a predetermined face by a photographic lens.SOLUTION: An attachment optical system for light-guiding a primary image formed on a predetermined face by an imaging lens to a photographic lens in a camera body is configured so as to be attachable/detachable to/from a camera body, and constituted of a first lens group with a negative refractive power and a second lens group with a positive refractive power from the predetermined face. When at least a partial lens group constituting the first lens group and the second lens group is moved to an optical axis direction, the photographic range of the primary image in the case of imaging the primary image formed on the predetermined face by the photographic lens is changed between a wide visual field and a narrow visual field. Thus, it is possible to appropriately set each of focal distances f1 and f2 of the first lens group and the second lens group. |
