Bokeh is rendition of out-of-focus points of light. This is different from sharpness and very cool effect that available in high quality and expensive cams but technology is very advance and some company offers the bokeh effect apps without any cost. Bokeh describe the out of focus area. Good bokeh does not happen automatically in lens design. Real lens have some degree spherical curve that shows lens is in good position and have ability to capture good quality bokeh.