The Leica 18mm Summicron-C Lens. The Leica Summicron-C lenses offer sensor coverage up to and including Arri Open Gate and RED Dragon 6K with an image circle slightly wider than 36mm in diameter. The classic linear focus scale of the SUMMICRON-C lenses is familiar to camera assistants around the world. Focus rolls in gently allowing for smooth pulls without the unpleasant sudden snap of sharpness or softness. The Leitz SUMMICRON-C primes utilize the most modern design and manufacturing techniques, resulting in a timeless set of lenses that capture the creamy texture of the world without any sacrifice in sharpness or contrast.