X4 CPL 58mm Circular Polarizer Filter - Schott B270 - MRC16 - Nano Coating - Weather Sealed - 25 Year Support by Breakthrough Photography

Great polarizer!(For those who thinks it doesn’t work, it doesn’t reduce light as much as cheaper ones, so it *appears* to be “not working”. Try standing in front of a mirror with the polarizer and flip it around a few times and you will see in the mirror that it is blocking light just fine.)Like other polarizers, it is quite thin, and not trivial to get back off your lens unless you use a rubber band around it to get a good grip. Before you say it, yes, I agree, they should provide that with the filter (and probably with GND filters too).Check the results with and without the polarizer in water, sun at a cross-angle to you, snow, and so on. You will be very pleased with the results!

There's nothing more expensive than a cheap mistake.Put simply, Breakthrough's X4 series is the best polarizer on the market, with the best customer service. The index markings are brilliant, the light transmittance is remarkable, and the polarization without flaw. Zero sharpness degradation; this plays very nice on 45mp and 60mp sensors. I was a Hoya HD3 fan, but these manage to be just as good for less money, as well as having features the Hoyas don't: Index markings, coatings that don't attract dust like it's somehow worth keeping, etc.The warranty coverage on these is excellent, from what I've heard. This is my fifth CPL from them, however, and all see regular use, but I've yet to encounter a single issue. I can't say that about any of the less expensive options I tried ... and with 95mm diameter lenses, it's tempting to try, but with a 30-year warranty it's safe to invest.Highly recommended. I now buy no other brand for serious purposes. These are functionally perfect.

Quality filter. No problems with the threads. Made of brass, so very sturdy.

TL;DR: X4 if you have the money or NEED the best. Gobe if you're willing to correct white balance in post.After recently deciding to buy a CPL for my camera, I whittled the available options down to two -- Gobe 3 Peak (Schott), and Breakthrough Photography X4.On paper, the Gobe has the same specifications as the X4: Schott B270 Glass and 16 layers of coating.The X4 boasts that it's coatings are unlike any other, and that it is able to capture the highest level of sharpness while maintaining perfectly neutral colors. Many comparisons have shown that the X4 is top dog against all the major players. However, I could not find a direct comparison against Gobe and hence decided to give both of them a shot myself.Sharpness: I could not find any significant difference in sharpness between the Gobe and the X4. They are both spot on and do not appear to affect sharpness in the least.Colors: The Gobe definitely shoots "warmer" than the X4. The X4 comes out neutral as advertised. If you seeking out-of-camera accuracy, the X4 wins hands down. However, the Gobe is only SLIGHTLY off, and it can be corrected in a single Spot White Balance click in your post processor of choice. Since most serious photographs will do some amount of post processing anyway, this is not a huge deal. I don't think the average amateur would even notice the difference without a side by side comparison, anyway.Polarization: Both filters were very effective in removing glare in my tests. I could not find a significant difference between the two.Production quality: Both filters are quality products, but the X4 wins here again. The grip portion of the X4 sticks out much further and it easier to screw on and off as a result. The Gobe is much more likely to get stuck on a lens with its design.Extras: The packaging of the X4 was surprisingly hard to open and seems that they tried too hard to make it seem "nice". The amount of jostling that it took to separate the box parts was excessive considering that there is a $160 piece of glass inside it. Gobe on the other hand uses modest packaging and also plants trees with the money they make from their products.Final opinion: The X4 is the better product but, for me, it is not worth the extra $100 that I could instead spend on adding ND filters to my collection. If money is no object or you demand the best, get the X4. If you don't mind a touch of white balance correction and a slightly lesser product in general, get the Gobe.I have included some pictures of my tests. In all pictures, the order is: No filter, Gobe, X4. The car is demonstrating the polarization, and the text is a 100% crop to compare the sharpness.