"For the time being, Japan, and especially Sony, we focus mainly on the definition and bokeh. With 36 million pixels on the Alpha 7R, we have not room for error. For bokeh we worked to minimize what we call the "onion rings" these concentric light halos around lights round blurred background. We must not neglect the bokeh, especially for a goal as Sonnar 55 mm f / 1.8 is primarily intended to be used to the full opening. We have, for example, designed the diaphragm so that it is as round as possible for a good blur and creamy background. This is much more difficult as people think because in addition aspherical surfaces in our objectives to correct chromatic aberration and coma, we tend to get blurred backgrounds ... a little too clear! "