I have recently been playing with the DOF to produce some artistic scenes: I have a wine bottle on a table in the middle of a room and the camera is at the edge of the room. I can make the label sharp, but not the bottle; (Bottle glass: 80% opacity, 0% roughness, flat colour. label: imported image, 100% opacity, 90% roughness) If I make the opacity 100% it sharpens up perfectly.
This is a current limitations of real time DOF approaches. We are aware of that and as soon as there’s a feasible solution, we will implement it.