B+W is a very popular high quality German camera filter brand which is known for high quality expensive filters. Usually B+W filters cost you more than $100 so its not something for point and shoot cameras like Canon Powershot SX20 IS cameras. These B+W filters are used by professional photographers who do serious photography and usually they have big budgets.
Recently I have seen B+W 58mm UVA (Ultra Violet) Haze MRC Filter
for $38.50 at Amazon.com If I hadn’t bought my Hoya 58mm Super-HMC PRO 1 UV filter then I would have definitly but this great high quality B+W UV filter
for my camera. Hoya is a quality brand but B+W is even better. So I’m sure you would know about B+W if you have been in this field for a while. So I think this is the best UV filter I have seen which you can buy for reasonable price. B+W 58mm UV Filter
for Canon Powershot SX20 IS camera is deal you wouldn’t regret later. I have seen 20 customer reviews about this B+W 58mm UV Filter at Amazon.com
and all of them given 5 star rating for this ! I think for 38 bucks, this B+W 58mm UV Filter
is a killer deal. Just by looking at the photo you can feel its a high quality UV filter.