The wide aperture allowed a very considerable reduction in exposure times. The lens, with the widest relative aperture of any then made (about f/3), was very successful for its intended purpose: the making of daguerreotype portraits. In 1840, the Hungarian Josef Petzval designed the innovative Petzval lens for Voigtländer. In the 19th century, Voigtländer made optical products including opera glasses and periscopic lenses. Another son, Friedrich Voigtländer, took control in 1808. Voigtländer died in 1797, and the company passed to his widow and two eldest sons, Wilhelm and Siegmund. to measure and divide distances and angles with great precision) which were used for calibrating surveying and navigational instruments including astrolabes. For example, Voigtländer invented instruments for linear and circular measure (i.e. Voigtländer was an optician and inventor, noted for his work on mathematical instruments, and held letters patent (a state-protected monopoly, the forerunner of a Patent) from the Austrian government, granting an exclusive right to carry on that business. Voigtländer was founded in 1756 in Vienna, Austria by Johann Christoph Voigtländer, as a scientific instrument maker. Image by eBayer Yalluflex ( Image rights) pronunciation 'FOYKT-lender') was one of the the world's longest-lived camera and lens makers.
