Which polarized filter for my tamron 17-50mm lens?

[sinitry23]

I've narrow it down to a B+W polarized cicular filter. But after browsing around BHphoto.com there are so many type of polarized filter. What is the difference? I'm looking to spend some where between $50 - $80 on a filter.

Is it worth it to spend over $100+ for a polarized filter? I should get circular polarized filters ?

[Jon]

You need a circular polarizer; there's a beam splitter, which will be affected by polarized light, used to deflect part of the incoming light to the AF sensors. With a circular polarizer, unlike a linear one, the light's "de-polarized" after the bad rays are filtered out. You also need a multi-coated filter (B+W calls theirs "MRC"; this shows up at B&H as "MC" for some reason) to minimize reflections and flare from the filter. Kaesemann are nice but not essential. They're essentially a "weather-sealed" filter, and probably 90% of polarizer use is on nice, sunny days (or indoors). For the 17-50 you shouldn't need a slim filter though. A "warming" filter's not really a great idea unless you already have a straight CP on hand. Get the best one you can afford, by all means. I think this (http://www.bhphotovideo.com/c/product/9776-REG/B_W_66044842_67_mm_Circular_Polarizer.html) would be my suggestion.

[canonpink]

Is it worth it to spend over $100+ for a polarized filter?

yes. I recommend Heliopan.