20 ms·

True, but the resolution needed to perceive the edge as not sharp on a typical display is far higher than the resolution of the image itself. Or reformulated:

• sudosysgen 6y ago
  That's true, but we're really getting there fast. My very sharp Minolta F1.4 full-frame lens is diffraction limited already at f/8 to f/11 at a definition of 6000 x 4000. It's also much, much sharper than the vast majority of pictures people take. While yes, 6000x4000 is a lot, monitors are already coming out with higher resolutions, so it's relevant right now. The fraction of images taken at an actual resolution so high that it has to be down scaled on a 6K or 8K monitor in practice is exceedingly thin. Even with a Sony A7RIV, an insane camera, and mind boggingly sharp lenses, most of your pictures after the Bayer filter and taking into account sampling (which is very real in photography due to Moire), most of your pictures either due to depth of field, optical abberations or motion blur, will not be at the level where you can create a truly sharp line of frequency higher than that between two pixels. So while it is often true, this is increasingly not the case.