[PyMOL] How to make protein blur but keep ligand clear?

Dear all,

I have a protein-ligand complex and I wish to make the protein looks blur but keep the ligand clear and sharp with pymol. I find a "focalblur" script (https://pymolwiki.org/index.php/FocalBlur) which seems to be able to do this. However I can get the fancy effect illustrated in the examples of the wiki for this script. With the follow command:

FocalBlur aperture=2,samples=10,ray=1,width=1000,height=1000


I just make the ligand rather the the protein become blur (Please see the image at https://drive.google.com/open?id=1qzXDLzVyxI85sJ8H6Zhv8pd8Cq7rA18U, and the pse file used to make this image is availabe at https://drive.google.com/open?id=1Gjrl5ePifadWEK8-AZYVXY7yX07kOLF7).

 Could anyone help with this？ What does the argument "aperture" do? How to control which part become blur?   Is there better way to make the ligand blur?

Thank you very much!

Arthur