Wals was born in Cologne. He worked as a landscape painter in Naples, Rome and Genoa, and died in an earthquake in Calabria in the late 1630s. He may have worked with the landscape painter Agostino Tassi (about 1580 - 1644) in Rome between 1616 and 1618. According to one of his biographers, Baldinucci, Wals then moved to Naples where he is thought to have taught Claude the art of painting landscapes. However, relatively few of his works have survived and his artistic career remains obscure.