Amazon.com : High Definition 52mm CPL Circular Polarizing Filter for Olympus M ED 9-18mm f/4.0-5.6 Micro Four Thirds Lens & Olympus M.ZUIKO Digital ED 12-50mm F3.5-6.3 EZ Lens : Electronics
Why You Should Use a Polarizer for Landscape Photography - CaptureLandscapes
What does a circular polarizing filter do and how do I use it?