Four-element lens systems of the Cooke Triplet family: designs.

Designs of three lens systems of the Cooke Triplet family with four-element configuration-Split Front, Split Back, and Tessar-have been developed with the help of a lens optimization program in identical conditions of optimization for use as 35-mm camera lenses. To evaluate the relative performance of these designs, their aberrational characteristics have been compared and contrary to popular belief, it is found that the Tessar is not the best among the four-element lenses of this family.