Distortion and Deliberate Distortion
The optical lens we don’t even think about is the key to taking good photos, whether with professional cameras or smartphones or the Hubble telescope. The next time you curse the camera on your phone, remember these lines from Simon Winchester’s book, Exactly : “Lens designers have discovered host of technical problems that can conspire to spoil a photographic image.” It’s all because of those long forgotten optics diagrams from school: Now for the English version of the best-known problems that cause distortions: 1) Spherical aberration : Light bends when it passes from one medium (air) to another (lens material), and this bending causes distortion; 2) Chromatic aberration : Even worse, light of different wavelengths (i.e., colors) bends by different amounts; 3) Vignetting : Difference in brightness between points at the center of the image and those at the edges; 4) ...