Great book about the major brands and achievements of German and Austrian optical industry. Many detailed photos, catalog pages and historical documents. A great source for identifying the objectives and an extensive bibliography to be explored by those who want to go deeper.
Among the time-honored firms, I only missed Goerz from Rathenow, the maker of Dagor, but which is only mentioned in the introduction.
Link to buy on Amazon: Corrado D’Agostini