I recently bought tiffen and b+w screw on filters ranging from .3-1.8 and they have'nt shipped yet but I was wondering if I made a mistake. I have different levels between diff brands. (.6, .9, 1.2-tiffen/.3, 1.8-b+w) If I want to add say a .3 B+W to a 1.2 tiffen will that create any odd shifts or degradation in quality or are you suppose to keep brands separate?