Converse telephoto die photographing glass lens null of riyahuokasu

摘要

PURPOSE: To provide an inverted telephoto photographing lens using a rear focus system having high optical performance over all object distances. ;CONSTITUTION: This lens is provided with two lens groups of a first group having a negative refractive power and a second group having a positive refractive power in order from the object side, the first group is provided with three lenses of a 11th negative meniscus lens whose convex surface confronts the object side, a 12th negative meniscus lens whose convex surface confronts the object side and a positive lens, focusing is performed by moving the second group on the optical axis and, by representing the focal length and the total length of lens of the first group by f1, DT1, respectively, the focal length and the total length of a whole system by f, DT, respectively, and an air gap between the first group and the second group at the time of focusing on an object at infinity by S, the conditions: 4|f1/f|6.5, 0.1S/f0.5, 0.25Dt1/DT0.5 are satisfied.;COPYRIGHT: (C)1996,JPO