| 摘要 |
Telephotographic objective of a wide angle of field consisting of six lens elements forming four lens groups separated from each other by airgaps, respectively. The foremost first lens group at the object side is a positive meniscus lens element, each of the second and the third lens group consisting of a composite negative lens group having a positive and a negative lens element cemented to each other with the negative lens element in each group facing to each other, the fourth lens group being a positive meniscus lens element. The concave surfaces of the first to three lens groups are directed to a diaphragm located between the second and third lens groups while the convex surface of the fourth lens group is directed to the diaphragm. |
