There is much speculation about the quality of this lens compared to the superb 55mm f1.8 SMC Takumar. Some assume that it will produce the same results from f2 onward due to its identical design. In quick preliminary testing I found it to be slightly softer and more prone to bokeh fringing in strong light. This could be due to a slight difference in lens coatings or it could be my particular test lens. From f2.8 it is sharp. Luminance and contrast are good. Colors are a bit cool. Focus ring dampening is superb. Shadow detail is excellent. Diffraction is not noticeable at f16. Bokeh fringing is noticeable though.