No lens is optically perfect. In the ideal world, every lens would produce a sharp, undistorted, evenly illuminated image that’s sharp from edge to edge. Some lenses come close, but the fact is that lens designers have to work within the limitations of the laws of physics and the glass materials they have available, and […]
Aberrations
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.