I'm thinking about adding a screw in polarizing filter to my camera bag, after reading many reviews I have short listed the Hoya Pro 1 and the Marumi DHG Super. My budget is 65 and this is the cost of the Marumi, the Hoya sells for 58.
Can anyone give me any advice, they will be attached to a Sigma 17 - 50mm lens that's already got a Hoya Pro 1 lens protection filter fitted.

Kind Regards