XA (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.

The 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.

Sony'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, and reliability, while also providing AF control that is quiet and virtually free of vibration.

Although it is a 135-mm telephoto lens, a floating focus system that effectively controls aberration at all focusing distances has made it possible to achieve a minimum focus distance of just 2.3 ft (0.7 m) and a maximum magnification of 0.25x for close-up photography. Small accessories and other subjects can be captured with remarkable resolution and soft, beautiful background bokeh.

The important features include customizable focus hold buttons, a focus range limiter, an aperture ring with switchable click stops, a dust/moisture resistant design1, and a fluorine coated front element. Overall, this is a lens that meets professional requirements for control and reliability for both stills and movies.