An F1.8 135 mm prime with superb resolution, bokeh, and AFUnsparing application of Sony's most advanced optical technologies has produced a large-aperture prime telephoto lens that delivers outstanding corner-to-corner resolution even at F1.8, plus exquisite bokeh that is a hallmark of the G Master series.XA and Super ED elements deliver high resolutionXA (extreme aspherical), Super ED (extra-low dispersion) glass, and ED glass elements precisely deployed in an advanced optical design effectively correct aberration, while a floating focus system works with these aberration correction measures to ensure that the highest possible resolution is maintained right out to the image edges throughout the lens's focus range.Narrow depth of field with breathtaking G Master bokehThe extremely high surface precision of XA elements, careful control of spherical aberration at both the design and the manufacturing stages, and an 11-blade circular aperture all come together to produce spectacularly smooth, elegant G Master bokeh that maximizes the creative potential of the narrow depth of field available with this 135mm F1.8 lens.Dual front and rear XD linear motors achieve fast, precise, quiet AFSony's innovative XD (extreme dynamic) linear motors also play an important role, making it possible to maintain focus on moving portrait subjects, performers on stage, or similarly dynamic subjects with impressive speed, precision,