Erweitertes Triplet-Objektiv aus mindestens vier in Luft stehenden Gliedern

摘要

A relatively powerful objective of relatively wide aperture having at least four elements of the expanded triplet-type situated in air. The objective includes a forward component made up of three elements and including a rear negative element which is followed by a rear component. The front element of the forward component has a concave hollow front surface directed forwardly toward the object and this front surface has an overcorrecting action. The various elements of the forward component provide it in its entirety with a biconcave configuration, and the limits of the ranges used for the various parts and groups of parts of the objective enable it to achieve a highly efficient optical action for an objective which has a relatively wide aperture in the range of from approximately f/4 up to f/1.8 or greater.