B+W F-Pro or XS-Pro... Best value in a top quality C-Pol!

You probably need an 82mm for that lens (earlier version of it used 77mm).

$137 for a B+W F-pro 82mm C-Pol. This filter uses German Schott glass, Kaesemann design (foils and weather sealing), and uses a relatively low profile brass frame (less likely to get stuck). It's a "high transmissive" type of C-Pol, which isn't as dark as most and allows approx. 3/4 stop more light to pass. The F-Pro also has very good 8-layer multi-coatings.

$143 B+W XS-Pro is the same in all specs, except it uses a "slim" frame (not necessary on a 24mm lens, the F-Pro works fine on my Canon 24-70mm, even though it uses the 77mm). More importantly, the XS-Pro has 16-layer "Nano" multi-coating that's more resistant to water, oil and scratches. It makes the filter easier to clean, compared to standard multi-coatings.

Compare to....

Heliopan 82mm High Transmission C-Pol with virtually identical specs as XS-Pro.... $241 (choice of standard or slim)

Sony T* (Zeiss?) 82mm C-Pol... $228

Hoya 82mm HD3 C-Pol... $224

Heliopan 82mm C-Pol (not High Trans)... $220 (choice of standard or slim)

Zeiss T* 82mm C-Pol... $203

Nikon 82mm C-Pol II... $179

Hoya 82mm EVO Antistatic C-Pol... $170

Hoya 82mm NXT C-Pol... $150

Yes, there are also some less expensive than B+W, but they are typically lower spec or a company I don't recognize.

I've used B+W filters for many years (also Hoya and others). I'm happy with them and they are still my first choice most of the time. But just for fun I recently bought a couple K&F Concept C-Pol to see what they're like (43mm and 72mm). Supposedly the "green" version I bought also uses Schott glass and has 18-layer "Nano" multi-coating. They aren't "high transmissive" and don't use Kaesemann foils (which I think may be exclusive to B+W). I don't know if they are sealed for weather resistance and the frame is slim, but aluminum. But, by being made in China they're CHEAP! B&H Photo has them in 82mm size for $50! (I bought direct from China for even less, but it took a few weeks to get them here.) I haven't used these K&F filters enough to say how good of bad they are, or to be able to truly recommend them... So if you decide to give them a try, you're buying at your own risk! I can tell you they LOOK decent (no problems with stiff rotation or threading onto lenses, with on the ones I got). We'll have to wait and see how a bunch images done with them look...That's what's important, after all. They are just about the least expensive multi-coated CPL anyone makes with Schott glass.

John those who are expressing "Opinions" without knowing what genere you work in or your current kit are at best "Talking Heads"... Especially if they don't document their inferences...

That said I see you are currently shooting BIF with a Nikon D500 and the AF-S 80-400mm f/4.5-5.6 (a pumper).
Your work is beautiful! Your Febuary 17th imagery of "Glide Path" is epic... Kudos on your expertise...

Ok, the AF-S 200-500mm f/5.6E ED VR is not the glass you need to take your work to the next level...
Yes I have this lens and quickly became disappointed with it for shooting League Soccer.
While it has excellent acuity it can not be rotated in it's tripod mount while shooting... Sadly Nikon warns to "Lock Down" this lens BEFORE shooting. This is a deal breaker for action sports and BIF. It will jump out of it's track and lockup on you.

I've migrated to an AF 300mm f/2.8 and have never looked back... The focus speed is truly several orders of magnitude faster (and far more accurate). My hit rate with League Soccer more than tripled!

If you stay in your current genre an IF prime will take you so much further than that "prosumer" Pumper... This pumper will fill with particulates over time... John there are many compelling reasons why commercial shooters use primes... for me this experience was a very brutal teacher... don't make this mistake.

Ok the 200-500 does work for studio and location fashion and beauty... below are examples of my efforts with this piece of glass... Yes it does have fabulous VR albeit since you are shooting at 1/3200 VR is virtually meaningless...

Hope this helps neighbor... we both live very close... lol
Oh, the Blackwater National Wildlife Refuge in Cambridge, Maryland is one of the finest BIF locations in the entire country. Enjoy!