Fix Vignetting and Other Lens Defects: Learn to Use LCPs (and DCPs)
Vignetting, chromatic aberration, and deformations like barrel distortion. Every lens has defects like these to some degree or another. While in some pictures they may be hidden, in others they are visible. Fortunately they are easy to suppress. You just need to install the DNG converter and take advantage of LCP (and DCP) profiles.