I am looking at getting the CLA-4 55mm lens adpaptor for my C-750. Can someone tell me if this allows any 55m lens to be attached (providing they have the same attachment method) or can only olympus lenses fit? Also, I would like to get a fish eye lens that can give me 180 degree scope, but the olympus website only lists a .7x wide angle. Can I get just any 55mm fisheye lens? Are there any pros or cons to consider? Thanks in advance for your help.