Buttery Smooth BokehMitakon Creator 135mm f/2.5 renders an exquisite bokeh by 9 blades of circular aperture. The background is softly blended like butter. Great control of depth of field can be achieved with focus technique, offering high level of creative potential with the lens. The perfect separation of subject from the background makes the lens ideal for portrait photography.Premium Image Quality - Ultra Sharp, No VignetteZhong Yi has improved the optical design of Mitakon Creator 135mm f/2.5 lens based on experience of producing 135mm lenses. 2 Super Ed (extra-low dispersion) glass and 2 ultra-high refraction Index glass elements are precisely deployed to provide optimal sharpness. Images taken by it are showing sharp details even across the corners, with minimal field curvature to ensure the highest possible resolution is retained along edges of the area in frame.Apochromatic (Apo) LensSuper Ed and ultra-high refraction Index glasses incorporated design of Creator 135 f/2.