View through a Petzval Lens

The Petzval lens was designed by Joseph Petzvel of Slovakia in 1839. It was designed around the time of the first daguerreotype camera. Its purpose was to reduce the extremely long exposure times of the daguerreotype camera from about 30 minutes to about 30 seconds, using a wide aperture. The Petzval lens was optimized for large apertures and indeed could only operate at one fixed aperture. Petzval lenses were the mainstay of camera and projection lenses for almost 40 years during the dawn of photography. They are very rare now. I was allowed to borrow such a lens produced by Bausch & Lomb for a few days from a friend in the US. These lenses were used for portraiture. They were very sharp in the centre, but had a marked drop-off in sharpness as well as introducing field-curvature around the edges. The particular lens used for the picture was manufactured around 1910.

- January 2007