An optical lens system for taking image comprises: a first lens element with positive refractive power, an Abbe Number of the first lens element being V1, and it satisfying the relation: 50<V1<60; a second lens element with negative refractive power having a concave object-side surface and a convex image-side...http://www.google.es/patents/US7813057?utm_source=gb-gplus-sharePatente US7813057 - Optical lens system for taking image
