Hello, The M.ZUIKO DIGITAL ED 75mm f1.8’s nine-blade circular aperture unit delivers beautiful defocused backgrounds, while the high-quality optical design keeps the subject in sharp focus. This is due to an advanced optical design that incorporates 10 lens elements in nine groups that make extensive use of special glass materials, including three ED (Extra-low Dispersion) elements to optimally correct aberrations. Each lens element is polished to an ultra-high level of working precision, only possible with the progressive techniques developed by Olympus master craftsmen, and carefully assembled to ensure maximum accuracy and reliability. Olympus’s exclusive ZERO (ZUIKO Extra-low Reflection Optical Coating) lens coatings are applied to the elements to reduce reflectance to a level that is half that of conventional coatings. Available for pre-order.