Let me start by saying this lens is better than people say it is. Focus dampening is good despite its age. Aperture is still positive and snappy. It's made very well. On the Eos M3 it handles very well. Focusing is easy and it's not too heavy. Sharpness and contrast at f1.4 are quite acceptable. At f2 it sharpens up slightly and it's crisp at f4. Color rendition from f2 up is very accurate. At f1.4 is renders bluish. Backlight causes a loss of contrast and overexposed areas are shifted toward blue. Fringing is practically non existent and that is impressive for a lens of its era being used on a digital body. Vignetting is visible at f1.4 and f2. It is gone by f2.8. Bokeh is smooth at f1.4 and with the vignette it takes on a dreamy look. Bokeh fringing can be seen at f1.4 thru f2. Flare represents as multicolored hexagonals. The sample pic below was shot directly into the sun; directly. One thing these vintage lenses excel at is black and white and this lens does an excellent job. Shadow detail and tonality are excellent.