Six element enlarging lens for multicolour reproduction - combines improved contrast with good colour correction over wide spectral range

摘要

The lens has an aperture ratio of approx. 1:4 with the diaphragm space bounded by two conveging meniscuses, each of which is adjacent to a cemented diverging meniscus with plane cemented surface, whereby each meniscus consits of an outer converging element and an inner diverging element and all the meniscus surfaces are concave relative to the diaphragm. The lens data provide good colour correction over a wide spectral range and improved contrast values compared with prior art lenses. The lens has a focussing range of approx. infinity to 1:2.