The Leica M system has several great portrait lenses. The Leica Macro Elmar 90mm f4, however, is often overlooked. While it doesn’t have the f2 of the Summicron, this 90mm is incredibly tiny, focuses in closer, and comes in a little less expensive. The build is a bit different than most M mount lenses, with a collapsable design that also helps the lens achieve infinity focus.