| 摘要 |
923,550. Photographic objectives. CARL ZEISS-STIFTUNG, [trading as CARL ZEISS [Firm of]]. Oct. 12, 1959 [Oct. 30, 1958], No. 34532/59. Class 97 (1). A photographic objective consists of five lenses of which the first is an asymmetrical collective lens which turns its surface of lower curvature towards the second lens which is also an asymmetrical collective lens which turns its surface of lower curvature towards the third lens while the third lens is an asymmetrical dispersive lens which turns its surface of deeper curvature towards the fourth lens and the fourth lens is also an asymmetrical dispersive lens which turns its surface of deeper curvature towards the fifth lens and the fifth lens is a biconvex collective lens, the objective being characterized in that:- (a) The sum of the airspaces between tne individual lenses is smaller than 30% but greater than 10% of the overall length of the objectives, wherein the overall length itself is greater than 80% of the focal length; The first lens is preferably a meniscus concave towards the second lens and the latter is preferably cemented to the third lens. Optical data are given for one embodiment of the objective illustrated. |
