In the last post we saw how EF established Canon as camera market leader, keeping mediocre DSLRs afloat well into the final chapter of the previous decade. EF lenses were critical. These lenses helped in the transition to Canon’s own mirrorless cameras and with EF, users were locked into Canon’s ecosystem, despite the growing threat of mirrorless in the second half of the 2010s. During that time EF even became…