Depth of field


I'm just experimenting with depth of field to simulate a realistic camera. But, I have problems with the parameters. I have a plane which should be displayed sharp. Before and behind that plane, the objects should displayed blured. My plane has the depth=30=>dofPass.setFocalPlaneDepth(30); The objects behind the plane: dofPass.setFarBlurDepth(40); The objects before the plane: dofPass.setNearBlurDepth(25); I tested with the last one other values, but I did not reach to view unsharply displayed near objects. I saw that only with far objects. Has anyone an example for that?

At dof_3_dof_2.frag, I saw numbers written to a vec2 samplesXX variables. What do they mean? How are they calculated? Has anyone links to (scientific) papers how this effect is working? I would like to know, what I'm doing  ;).