First, I doubt you need a "slim" filter on a 24mm lens. I've never needed one on even wider lenses.
That said, there are a number of good brands of Circular Polarizers. For my money, B+W are really hard to beat. Excellent quality at a reasonable price.
You probably need an 82mm filter. And I'd recommend multi-coated for outdoor use under a wide variety of conditions.
B+W XS-Pro Kaesemann Nano MRC C-Pol is their top-of-the-line and an 82mm costs $117. That's a "High Transmissive" filter, which is lighter gray than standard C-Pol, so it "costs" less light lost to the filter. It's made with German Schott glass, uses fine Kaesemann polarizing foils and is sealed for moisture resistance. The Nano-MRC multi-coatings are 16-layer, with added resistance to scratches, water, finger oils and easier to clean. It's mounted in a brass frame to reduce chance of getting stuck. And it happens to be a "slim" filter.
B+W F-Pro Kaesemann MRC C-Pol is one step down and actually selling for more right now, at $121 for 82mm. It's identical to the XS-Pro in many respects, but doesn't use a "slim" frame (can be a little easier to install, remove and adjust than slim filters). It use more standard, but still good and effective 8-layer multi-coatings.
B+W MRC C-Pol is another step down, though it too is selling for more than the XS-Pro, at $120 for 82mm. This is a "standard" C-Pol, not "High Transmissive", so it will cost between approx. 1.5 and 2.25 stops of light, depending upon adjustment (HT filters cost between approx. .75 and 1.5 stops). It also doesn't use the Kaesemann foils or have the add'l sealing, but it uses the same glass, coatings and frame as the F-Pro.
B+W SC C-Pol is a single coated filter that I would recommend primarily just for indoor use, under controlled lighting conditions. Assuming you want a more general purpose filter, I didn't look up the price for it.
There are some other, very comparable filters from other manufacturers...
Heliopan HT, SH-PMC, HT Slim and SH-PMC Slim C-Pols are virtually identical to the top two B+W, but the Heliopan filters cost $241, $220, $207 and $180 respectively in 82mm size.
Hoya HD3 and EVO Anti-Static are similar in quality and sell for $220 and $170 in 82mm size.
Breakthrough Photography X4 C-Pol is almost identical in specifications to the XS-Pro and sells for $159 in 82mm size.
More standard style (darker gray) Zeiss T* and Nikon II C-Pol are also top notch, with 82mm diameter selling for $203 and $178.
See more at:
https://www.bhphotovideo.com/c/search?Ns=p_PRICE_2%7c1&sortType=default&setIPP=48&ci=115&fct=fct_polarizing-type_35%7ccircular%2bfct_circular-sizes_27%7c82mm%2bfct_design_2321%7cmulti-coated%2bfct_polarizer-combinations_2322%7cplain-polarizers&srtclk=itemspp&ipp=48&N=4026728357&Sure, there are multi-coated C-Pols that cost less... but most don't come anywhere close to the specifications of the B+W filters. The filters that are comparable to B+W tend to cost more. In some cases a whole lot more! In my opinion, it's pretty hard to beat the value offered by B+W.
CO wrote:
...did you know that Nikon makes polarizing filters that are excellent? Nikon polarizing filters are not well known but their quality are right up there with the best. I have a 67mm one.
This is true of the Nikon "II" series filters. They're multi-coated. Earlier Nikon filters were not. FYI, Canon's filters still aren't multi-coated.
In general, camera manufacturers' name brand filters are not a particularly good value. They tend to be high priced for what they offer. Most are probably out-sourced anyway... Actually made by one of the major filter manufacturers and simply re-branded with the camera maker's name.
FWIW, B+W is a subsidiary of Schneider Kreuznach, a very high end lens maker for the last 100 years or so.