onion

Panasonic Cuts the Onion, Fixes Strange Effect Caused by Aspherical Lenses

Have you heard of the "onion ring" effect in bokeh? It's a rather obscure term that emerged as lenses began featuring aspherical lens elements to reduce aberrations and reduce size. Due to the way aspherical lenses are produced, strange "onion ring" lines can appear in out-of-focus points of light.

The term may also soon be a thing of the past: Panasonic has reportedly figured out how to cut the onion (effect), allowing aspherical lenses to produce smooth and pleasing bokeh.