X4 CPL 55mm Circular Polarizer Filter - Schott B270 - MRC16 - Nano Coating - Weather Sealed - 25 Year Support by Breakthrough Photography

I photograph real estate and architecture for a living and a CPL filter comes in really handy for reducing reflections in interiors and giving a deeper, saturated look to exterior shots. I have noticed no color casts from this Breakthrough filter and the build quality seems great. The markings on the side are a neat and helpful addition as well. I have only used it on one shoot so far but it was very helpful for reducing reflections on shiny wood floors.

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.

Made in U.S. based out of San Fran.25 year warrantySpecialty neutral coated Schott glass. On the inside of the fiterl & the outside of the filter.No color cast.No vignetting.Images stay sharp.Excellent, SUPERIOR quality.***From their website - READ***The X4 CPL features SCHOTT Superwhite B270® optical glass, which is an ultra clear crown glass. It is produced by melting high purity raw materials and then made using the continuous draw process. The result is excellent transmission in the ultraviolet, visible, and infrared spectrums, and a high surface quality that accepts our state-of-the-art MRC and nanotec® coatings exceptionally well.Our state-of-the-art multi-resistant coating (MRC) is an optical coating applied to both surfaces of the glass disk to reduce reflection and to increase surface durability. Our proprietary MRC coating is structurally harder than the glass itself and the reduced reflections improve the efficiency since less light is lost. The reduction of reflections also improves the contrast of the image by elimination of stray light. The real world result? Better contrast and color.Low light transmission and green flaring are common problems with uncoated glass. As MRC coatings are added to each side of the optical disk light transmission steadily increases with flaring steadily decreasing. In our lab tests light transmission apexes at about 16-layers of MRC, and slowly decreasing in transmission at 18 and above. 8-layers of MRC are applied evenly to both sides of each optical disk resulting in MRC16.

Very well built item and high quality glass. My only complaint is that they are tight when turning the element to adjust polarization. That may change as it is used but for now it's a bit hard to adjust. Other than that you can tell this is a high quality item right out of the box.

Best filters available.

The imaging is top notch, and the threads are metal that fit perfectly. Adjusting the filter is smooth and has just the right amount of resistance.

Very smooth, well designed!

Colour neutrality is phenomenal. Most other CPL impart some “warming” to the image

This pro level filter even has its own product number. The protective case supplied is the best I have seen for any filter.

Breakthrough Filters are the best filters I have used (and I have tried a good number through the years). No colour shift with the Polarizer - the combined Polarizer and ND are take away the need for using more than one filter enabling you to hold the detail. And always packaged incredibly well. Would highly recommend.Used on my Nikon D810, 77mm lenses.