411 REFERENCE · Wiktionary
Petzval lens
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Etymology
Developed in 1840 by Joseph Petzval.
Noun
en historical A photographic lens consisting of two doublet lenses with an aperture stop in between.
Related terms
en Petzval condition
en Petzval sum
en eponyms
en Photography