When Leica lent me their new Super-Elmar-M 21mm f/3.4 ASPH lens, I gave a figurative shrug. I already owned an excellent copy of an old 21mm f/2.8 Elmarit pre-ASPH, which I absolutely love. So it would be highly unlikely that Leica’s new 21mm would actually inspire a case of gear lust… but gear lust I…