Zeiss Normal 50mm f/1.5 C Sonnar T* ZM Manual Focus Lens for Zeiss Ikon and Leica M Mount Rangefinder Cameras - Black Virtually zero geometric distortion for accurate reproduction of object shapes, particularly products and architecture Reduces unintended focus shift with aperture variation for improved accuracy of rangefinder defined focus Precise 10-blade aperture with 1/3 stop interval click stops ensures exact exposure Wear resistant filter mount for long-term reliability in tough conditions Highly advanced flare control that ensures crisp, brilliant images