I've had a little fun, with a K-Series 55mm f1.8 on an un-named camera over the last few days.
When I captured this photo of a Rock.


Although it was windy today I took the same lens out, and shot at f2.8, or wider open.
Capturing these 2 photos.



You've got to love the bokeh this lens can produce
I don't know why I rarely use it.

You captured the flowing water well in that first one Stu.