I have just taken my first foray into adapted lenses by buying a Olympus Zuiko Standard Lens 50mm. I want to make sure I get the correct adapter. Is there a difference (except for price) between these: 1. Olympus OM lens to Micro 4/3 Adapter EP2 E-P2 E-P1 PEN | eBay 2. Professional Olympus OM to Micro 4/3rds Lens Adapter Ring. M 4/3 Mount Adaptor. | eBay or, can anyone recommend a particular brand? I see lots of items from Roxsen for sale (from Hong Kong), and they're half the price of the other items.