| 摘要 |
<p>A rear attachment lens (LA) that is capable of being detachably attached to a main lens system (LM) at an image side of the main lens system (LM) to lengthen a focal length includes a first negative lens (N1), wherein, when V d_N1 and ”¸ gF_N1 are an Abbe number and a partial-dispersion-ratio difference, respectively, of a material of the first negative lens (N1), f _N1 is a focal length of the first negative lens (N1), and f is a focal length of the rear attachment lens (LA), the following condition is satisfied: 0.00015 < ” �¢ ¸ gF_N �¢ 1 * f / ½ d_N �¢ 1 * f _N �¢ 1 < 0.00620.</p> |
