An Albada zoom finder includes a first lens assembly of positive power, a second lens assembly of negative power, a third lens assembly of negative power and a fourth lens assembly of positive power, arranged in this order from the object side of a camera. An Albada frame is provided on the lens surface...http://www.google.es/patents/US5353158?utm_source=gb-gplus-sharePatente US5353158 - Albada type zoom finder
