Introduced in 1953, the Zunow 50mm f1.1 lens boasted the brightest aperture in the world at the time, emerging just eight years after the end of World War II. Its arrival sparked a competition among Japanese manufacturers to produce ultra-large aperture lenses, leading to the release of a series of captivating lenses from various companies that continue to enthuse us to this day. This particular item is a mid-production model of the Zunow 5cm f1.1 with serial number in the 5000 range, featuring a Leica screw mount and manufactured by Zunow Optics. It bears the rare Meter distance scale marking on the helicoid, uncommon for Zunow lenses. Compared to the early models, known as the "ping-pong" due to the protruding rear element, this version has a smoother lens mount detachment and appears to suppress flare near the wide-open aperture. Although Zunow produced various iterations in a short span, this type is likely the most commonly seen. Its elegant barrel design with rhythmic grooves and an iconic brand name "Zunow," coupled with its penchant for extravagant flare when wide open, surely stirred the hearts of post-war Japanese people as the world's brightest standard lens, despite its brief existence. It remains a unique and compelling piece of Japanese engineering with an enchanting story. As you stop down from wide open by one or two stops, the rendering becomes notably sharper, offering a different photographic experience akin to another lens. Whether admiring its aesthetics or capturing images, it's a lens that excels in both aspects. Comes with an original front cap. A rare find indeed. There is a single mark near the base of the lens barrel, likely from a previous drop, but it does not affect focusing or rangefinder coupling. Otherwise, the lens exhibits minimal signs of use and maintains a clean exterior appearance. Including focus adjustment, fully serviced in 2022. Thorough maintenance has preserved its superb operational feel. Unlike typical Zunow lenses, there is no wobbling in the lens barrel or stiffness in the helicoid, ensuring smooth and stress-free distance adjustment. Rangefinder coupling works perfectly. The lens shows very minor coating deterioration, but there are no noticeable wiping marks or haze, resulting in exceptionally clear and beautiful glass. Practical shooting tests yielded highly satisfactory results.