An interesting story is told on
http://www.wisskab.com/presse/5_weber-unger.pdf
it relates the Petzval Lens, the Voigtlander History and the Brazil's Emperor.
For those interested in new Petzval lenses,
a new link at
https://www.kickstarter.com/projects/lomography/the-lomography-petzval-portrait-lens
could be viewed.
Best regards
LP
02/21/2014 20:03