Petzval lens

The Petzval objective, or Petzval lens, is the first photographic portrait objective lens (with a 160 mm focal length) in the history of photography. It was developed by the Hungarian mathematics professor Joseph Petzval in 1840 in Vienna, with technical advice provided by Peter Wilhelm Friedrich von Voigtländer. The Voigtländer company went on to build the first Petzval lens in 1840 on behalf of Petzval, whereupon it became known throughout Europe. Later, the optical instruments maker Carl Dietzler in Vienna also produced the Petzval lens.