| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an attachment optical system capable of leading a luminous flux from a primary image to a photographic lens while the entire system is small-sized and an excellent optical performance is maintained, when re-imaging the primary image formed on a prescribed surface by the photographic lens. <P>SOLUTION: An attachment optical system At guides the primary image formed on a prescribed surface 21 by an imaging lens 10 to a photographic lens 31 inside a camera body 30, the attachment optical system is attachable and detachable to/from the camera body, and the attachment optical system comprises a first lens group 22 of negative refractive power and a second lens group 23 of positive refractive power in order from an object side to an image side across the largest air gap. A focal distance f1 of the first lens group, a focal distance f of the entire attachment optical system, a distance d1 from the prescribed surface to a lens surface on the most object side of the attachment optical system, and a distance L from the lens surface on the most object side of the attachment optical system to a lens surface on the most image side are respectively appropriately set. <P>COPYRIGHT: (C)2013,JPO&INPIT |
