Olympus Zuiko 50mm f1.8​

     The Zuiko S 50mm f1.8 has excellent sharpness and a semi-smooth bokeh below F5.6.   

It is very easy to focu, even without AF confirmation, which makes it a good choice for use on a D-SLR.  Contrast is slightly high and colors are slightly cool.  Chromatic aberrations are very low.   

Olympus Zuiko 50mm f1.8​ review
Olympus Zuiko 50mm f1.8​ review