Aberrations, or optical imperfections, exist because no lens is optically perfect. Almost all lenses show aberrations from the ‘perfect’ image.
These are optical flaws produced by camera lenses and which are largely unavoidable except in the most expensive or the simplest lens designs. They include distortion, chromatic aberration (colour fringing), vignetting (corner shading) and edge softness.
Verdict: 4 stars DxO ViewPoint 3 is a very effective and useful add-on for DxO PhotoLab but perhaps less useful these days as a plug-in for Lightroom and Photoshop, given that these have pretty good perspective correction tools of their own. ViewPoint also faces competition from the new and very similar Perspective Efex plug in that’s part of the DxO Nik Collection 3.