You don't need anything special to get this in Corona, just plant a tree and lit a sun. This phenomena depends on two things - right distance between the leafs and the ground and many small gaps between the leaves. Usually it's not hard to get it fulfilled. Basically, it's the same DOF, it just happens not in a lens, but between the leaves and a ground. Gaps between leaves acts as an aperture and ground is a film, or sensor.