Wide angle lenses tend to be built with specificity in mind. They are rarely designed to be your main workhorse. When it comes to Leica brand lenses for M-mount, there aren’t many options for super wide-angle options. The Leica 16-18-21mm Tri-Elmar f4 lens offers three wide focal lengths in one compact design. You can compose one frame and easily change the perspective and focal length with the turn of a dial. It specializes in several genres quite well and makes it an excellent crossover lens. Keep reading to find out.