Review of the Breakthrough Photography X4 and X4 Dark Circular Polarizer Filters

June 9, 2020

I've been using circular polarizer (CPL) filters almost since day 1 of my photographic journey, and since that day, I have been searching the best filter possible. After years of being frustrated with CPL filters, I may have finally found a new favorite, the X4 Circular Polarizer made by Breakthrough Photography.

Before we dive in deep, I'll define what makes a filter the "best" CPL filter for me working as a landscape and travel photographer. First and foremost, I need a filter that has as little impact as possible on image quality, which means it does not degrade sharpness, it has to be as color-neutral as possible, and it needs to be multi-coated to suppress flare and ghosting. The filter also needs to be thin to avoid the issue of vignetting in the corners of the image frame when used on ultrawide angle lenses, but I also need a filter that is easy to work with under harsh conditions and can hold-up in those conditions. The filter needs to be scratch-resistant, easy to clean, and I have to be able to use it in these conditions including in the winter when wearing heavy gloves.

The Search for the Best Circular Polarizer

Over the years, I have used filters made by Hoya, Tiffen, Marumi, B+W, and many others. I'm fairly certain I started with the Tiffen filters, but they were thick and vignetted on my ultra-wide lens. I upgraded to the Marumi Super DHG filters, which were much thinner, but I was noticing a colorcast in most of my photos.

Next up was the Hoya HD filters, which were thin, very color neutral, and offered 25% Greater Light Transmission than most other circular polarizer filters from other brands. The problem was that they are known for falling apart, which I, unfortunately, learned in the middle of a backpacking trip to the bottom of the Grand Canyon. As I was twisting the filter to adjust the amount of filtration, the front half separated from the rest of the filter and fell into the Colorado River. Luckily, I had a spare filter on another lens, but I found that I spent the rest of the trip waiting for that filter also to fail, which it did just a few weeks later. This failure of the filter hardly passed my durability test.

At the suggestion of several photographers in the online photo communities, I switched to the B+W XS-Pro Kaesseman High-Transmission MRC-Nano Filter. This was finally a circular polarizer that ticked all the boxes for me, or so I thought. It is a thin, multi-coated, high-transmission filter with no noticeable color cast. I was in love with this filter, but only for about the first year. You're probably wondering what changed? The only downside I have found to this filter is that after some use, the filter becomes very stiff and almost impossible to turn. It got to the point that I could only turn it counterclockwise (from the point-of-view of being behind the camera) because if I turned the filter clockwise, I would end up unscrewing the filter from the lens. That's how stiff it got.

Breakthrough Photography X4 Circular Polarizer

Several years ago, I was gearing up for one of my 18-day photography expeditions rafting 225 miles of the Colorado River in the Grand Canyon. These trips expose a photographer's equipment to harsh conditions, including lots of sand, dust, and spray from waterfalls. I often find that I use CPL filters as a protective filter in these conditions, and they spend a lot of time on the lens. I didn't want to go through the trip dealing with my B+W filters, which were becoming increasingly difficult to adjust at the time, so I set out to find a new CPL filter that met all of my criteria.

Breakthrough Photography X4 circular polarizer filter review.

My search lead me to the Breakthrough Photography X4 Circular Polarizer, a brass-framed filter that has been designed for durability and top-notch optical quality. It features Schott Superwhite B270® optical glass and 8 layers of multi-resistant coatings (MRC) on each side of the glass to reduce reflection and to increase surface durability. The X4 CPL is available in a wide range of filter sizes from 39mm up to 105mm.

In my testing, I've found that this is a high-transmission filter, which means it has minimal impact on the amount of light getting to the lens. Most circular polarizers cause a loss of 1.5-stops of light, but the X4 CPL only causes a loss of 1-stop. This is great for those times when you want minimal impact on shutter speed, such as when you're working in low light.

Gear Used

I purchased a pair of the X4 CPL filters in 2017 and have been using them on several different camera systems, including the Fuji GFX 100 & Fuji GFX 50R with the GF 23mm f4 and GF 32-64mm f4 lenses, and the Sony a7RIII and a7RIV with the 16-35mm f2.8GM and 24-70mm f2.8GM lenses. I have recently begun using the Canon EOS R mirrorless camera with the RF 15-35mm f2.8L IS, and RF 24-70mm f2.8L IS lenses.

All of these lenses use an 82mm filter, except for the GF 32-64mm f4, which uses a 77mm filter. I used an 82mm filter on this last lens via Breakthrough Photography's 77mm to 82mm step-up ring. I have not seen any noticeable vignetting on any of these lenses, including the Canon RF 15-35mm f/2.8 L IS when used at 15mm.

Build Quality & Ergonomics

I've purposely waited to share my thoughts about these filters until I was confident in their ability to withstand the conditions I would use them in. The filter has held up very well, and I have not had a single failure of any kind.

Breakthrough Photography X4 circular polarizer filter review.

The X4 CPL is very easy to attach to a lens and is even easier to adjust; this includes using the filters in the winter when I'm wearing heavy gloves. I believe this is due in part to the knurled texture of the adjustment ring, and the ease with which the filter turns. I have had some difficulty in removing the X4 CPL as the rear half of the filter is incredibly thin, but I do understand that making it thicker would lead to the filter itself being thicker and then possibly vignetting on ultrawide angle lenses.

Another factor that is perhaps often overlooked when comparing filters is the ease of cleaning. The multi-resistant coatings contribute to keeping the filter free of dust or water droplets. Any dust that does manage to stick to the filter is easily cleaned with a rocket blower. The MRC also does a great job of repelling water droplets, but any that do stick are easily wiped away with a microfiber cloth. I have also found that fingerprints also wipe away just as easily.

Image Quality

I have yet to notice a loss of sharpness when using these filters, plus I see better contrast and less ghosting and flare when comparing to the other CPLs I have used in the past. Breakthrough Photography takes pride in making the best filter possible, and the X4 CPL is no exception. The Schott glass and 16 layers of MRC contribute to making the X4 CPL one of the best, if not the best, CPL available today from an image quality perspective.

Return of Sacred Waters

Waterfalls in the Deer Creek Narrows, just below ‘The Patio’ in Grand Canyon National Park. © Adam Schallau, All Rights Reserved.

The photo above of the waterfalls on along Deer Creek Narrows in Grand Canyon National Park was made using the Fujifilm GFX 100 medium format mirrorless camera with the GF 32-64mm f4 lens and the X4 circular polarizer. This camera is capable of capturing incredible detail, especially when focus-stacking multiple images to achieve maximum depth-of-field. The X4 CPL in no way degraded the image quality.

X4 Dark Circular Polarizer

If you've spent some time on the Breakthrough Photography website, you will notice that they offer a version of the X4 CPL with a neutral density (ND) effect built-in. This version is known as the X4 Dark and is available in a 3-stop and 6-stop option.

I'm not a fan of stacking filters, meaning placing one filter on top of another, as they can become stuck together, or you could end up with vignetting on an ultrawide angle lens. The X4 Dark allows me to avoid stacking filters by incorporating the CPL and ND into one filter.

Breakthrough Photography provided me with the X4 Dark 3-stop for my last river trip. I had the opportunity to use it photographing several waterfalls and some of the rapids in Grand Canyon, and I found that it has all of the same attributes of the X4 CPL plus the benefit of the 3-stop ND. In my testing, I did find that the ND effect is closer to providing a 2⅔-stops of filtration.

Shades of Cyan

The Colorado River at North Canyon in Grand Canyon National Park. © Adam Schallau, All Rights Reserved.

I made this photo of North Canyon Rapid at river mile 21 on the Colorado River in Grand Canyon National Park using the Fujifilm GFX 100 medium format mirrorless camera with the 32-64mm f4 lens and the X4 Dark 3-stop circular polarizer. The X4 Dark CPL allowed me to use a shutter speed of just over 3 seconds instead of a 1-second exposure that would have been possible with the X4 CPL. This was enough of a difference to get the effect I was looking for in the water.

My workshop participants often ask me if they should purchase the X4 CPL or the X4 Dark CPL with the 3-stop or 6-stop ND (neutral density) option? My answer, which is the same that I have to give to many of these questions, is that it depends. It depends on what you like to photograph and your approach to capturing the subject. If you like to make photos using long exposures, such as photographing waterfalls or wanting to smooth the ripples and waves on the surface of a lake or ocean, then the 3-stop or even the 6-stop version might be right for you. As for what's in my bag, I have both X4 CPL and X4 Dark CPL to fit different needs.

Pros & Cons

• High-transmission causing a loss of only 1-stop of light.

• No perceptible color cast.

• Minimal ghosting & flare.

• Durable and easy to clean.

• No vignetting on the tested lenses.

• Can be a bit difficult to remove due to the thinness of the knurled area.


In using the X4 circular polarizer, I have found that the only drawback is the difficulty in removing the filter, but this negative is far outweighed by the filter's positive attributes. Breakthrough Photography is making some of the best filters on the market. The X4 and X4 Dark circular polarizers are fantastic, and I think it's safe to say that I have finally found my favorite circular polarizer filters.