.  I researched EF glass and concluded that anything with a max aperture lower than f0.0 (like L glass) is mostly useless from softness/glow, CA. so you spend >$0K while almost always stopping down to f0.0 or smaller. So I concluded all I wanted was the Canon 00/0.0 or Sigma 00/0.0, and Canon 00/0.0. all of which cost less about $000 used. Better than Nikon options. But not necessarily better than Olympus options.  