Ok B+W 58mm Circular Polarizer MRC Filter might not be the best Circular Polarizer Filter for Canon SX10 or Canon SX20 cameras because this Circular Polarizer Filter is around $100. But if you also have a DSLR camera then B+W 58mm Circular Polarized MRC Filter is something you should keep in your camera bag. This is one of the highest quality Circular Polarized filter you can find. B+W is known for quality products.
It has brass Ring for higher Quality Image and highest possible polishing technique. New thinner Pro mount and No vignetting. If you check Amazon.com you will find 14 five star rating for this filter out of 14 total ratings. Every customer who has reviewed and written a feedback seems happy with it.