Fstoppers Reviews the B+W XS-Pro Kaesemann High Transmission Circular Polarizer MRC-Nano Filter

Fstoppers Reviews the B+W XS-Pro Kaesemann High Transmission Circular Polarizer MRC-Nano Filter

Many different lens filters for photography are steadily being replaced with multiple-exposure camera tricks and post-processing software tools. However, one filter more resistant to this change is the circular polarizer (CPL). This special tool filters the light entering a lens in ways that software has yet to be able to mimic realistically. The resulting images when using a CPL are more saturated with color due to cutting down reflections of haze, water, and other surfaces in the world around us. In this review, I take a look specifically at the B+W XS-Pro KSM HTC-POL MRC-Nano Filter.

These B+W XS-Pro CPLs are constructed using Schott glass, Kaesemann polarizing foils, and brass filter rings. Together, these should provide proper optical clarity and accurate, neutral color reproduction. The glass has a number of anti-reflective coatings to reduce internal ghosting and reflections, something that cropped up in certain lighting when I used cheap CPLs. It also features a multi-resistant coating (MRC) with a top “Nano” coating which equates to easier cleaning and hopefully a longer lasting clean from dust and dirt floating around.

To avoid vignetting while attached to the lens, the CPL’s outer diameter is designed to be wider than the filter thread size. Depending on one’s lens, this can interfere with mounting a lens hood. For me using a Sony 70–400mm G II lens, this meant I would need to take the bayonet-style lens hood off, install the CPL, then refit the lens hood.

In use, I found the B+W XS-Pro CPL to be more stiff than what I’d prefer for rotating the filter and changing polarization strength. This may be a testament to how well it’s sealed, but it can still be a usability issue when I needed to spin it using only one finger through the lens hood window of my Sony telephoto. Instead of playing a game of “will it move,” I just opted to always go from the front of the lens hood with my fist of fingers (blocking the view) to get it right quicker.

Another issue with this circular polarizer is that it can be quite difficult to remove from the lens. On more than one occasion I felt like an idiot in public fiddling with trying to remove the filter for an embarrassingly long amount of time. I swear, people, I know how my camera works! Don’t look at me like that! After a while it can make one start to question which way it’s supposed to be turning, only to start going back and forth a few rotations each while onlookers dial the police. I’m unsure if this is something that will improve years down the line as the lenses and filter adapt to each others tolerances. I hope so.

The “high transmission” portion of its name refers to the amount of light allowed through. Depending on what your intentions are with this filter, this may be an extremely important detail. If a polarizing filter has outstanding optical clarity, why ever remove it? Well, these filters knock out some of the light as it’s being polarized before it reaches the camera sensor. That means lower shutter speeds or higher ISO settings. The B+W XS-Pro CPL’s product sheet promises 99.5% transmittance for its Kaesemann foils, or up to 1.5 stops of light loss. In my shooting, I saw about a one stop difference between having the filter on versus off. That’s not bad at all when it comes to CPLs, and another area where the cheap filters struggle to keep up. None of this really matters, however, if the plan all along is to mainly use the filter for cases such as knocking out reflections in long exposure flowing water images, and may even be seen as a negative.

The optical quality while photographing through this filter was very satisfying. My previous cheap screw-on filter had real issues with ghosting that drove me nuts because it was impossible to detect on the viewfinder and only became apparent at full scale on the computer. With the B+W XS-Pro CPL, everything I was getting from the naked lens was appearing sharp and clear as ever with it installed, even on a higher resolution 42-megapixel camera.

The full power of a CPL filter.

There was very little polarization here as the sun was behind me rather than at 90-degrees from my scene. However, there's still some subtle improvements between the on and off images.

Photographing in nature after a summer rain shower can mean a lot of reflections and sheen on the foliage without a polarizing filter handy.

While not showcasing the full power of polarization, the lack of strong reflections from this wet cormorant's feathers meant a fuller black rather than a gray sheen.

What I Liked

  • Doesn’t appear to affect image sharpness or clarity.
  • MRC-Nano coating makes it easy to wipe clean.
  • Good transmission of light; One stop difference in my use.

What I Didn’t Like

  • Hard to remove.
  • Rotating the polarization ring is overly stiff to engage.
  • Interferes with some lens hoods.

While it suffers from some usability issues, I’m pleased with the final image output this polarizing filter produces. The B+W XS-Pro Kaesemann High Transmission Circular Polarizer MRC-Nano Filter is priced at $102.50 and is available now on B&H Photo.

Revision: A previous version of this article erroneously stated the filter came with a 10-year warranty. B+W has informed me this is no longer the case and is now covered under a 1-year warranty.

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This marks my first post, being new to the site. A couple of things:
First, Well explicated! Wonderful examples with excellent usage of the polarization/non-polarization (what the heck do you call that sliding technique?).
Second, I challenge your characterization of polarization as "altering the wavelength of light". As I understand it, polarization merely blocks that light that is not in the same plane. Not being a physicist i'm unable to describe it better.
I've been using polarising filters for forty odd years, and find them so important I can't imaging a serious photographer NOT having one in their bag. GW

Ryan Mense's picture

Hahaha. "Not being a physicist i'm unable to describe it better" basically sums it up for me too, as you can tell. I'll revise that sentence.

I'm looking forward to reading more of yours articles. GW

Ryan Mense's picture

Thanks, Greg!

Craig Tooms's picture

Greg I believe the script they are using for the image comparison is called TwentyTwenty.

"I've been using polarising filters for forty odd years, and find them so important I can't imaging a serious photographer NOT having one in their bag. GW"

They have their use but it's certainly not something a "serious photographer" needs. After all, it's not like our eyes see things that way. Personally, I've never been a fan of such a filter. I don’t even own one, though I do use polarizing sunglasses for safer driving.

Perhaps it's the type of photography. I shoot 90% outdoors, often around water; and through airplane, bus, auto, etc windows. You're right though, indoor and studio shots would almost never need such a lens. "It's not like your eyes see that way" is an odd thing to say about any photography, let alone modern digital/post. Tell me, thanks. GW

I don’t shoot indoors so my position on such a filter has to do with shooting outdoors. I simply don’t like the look of a polarizing filter in most cases.

" ‘It's not like your eyes see that way’ is an odd thing to say about any photography, let alone modern digital/post."

I don’t know about your type of photography but mine looks pretty darn realistic. If you are comparing the general adjustments that many, if not most, photographers make to their photos, then what is odd is to compare that to the effect of a polarizing filter. It's entirely unnatural to how our eyes see things.

Well Bob, I can't argue with that at all. As art, photography is all in the eye of the artist. Hopefully, as I navigate this new (and damn good) site I will find some of your work. Thanks. GW

Kyle Medina's picture

Glad yours was stiff to turn too. I've wondering if it was my copy or not. Yes B+W needs to fix that issue.

Maybe you just need to spend some time working it. That may loosen it up. Everything mechanical loosens up with use.

...."Kaesemann polarizing foils"....

Kaesemann are not the foils, it is the technique of cementing
(of the outer and inner glass with coresponding foils and rings).

....."Hard to remove"...

For a few cents there is a B+W tool for removing extensively tightened filters.

Ryan Cooper's picture

I suspect the reason it is so hard to remove is that the circular polarizer spins freely so its hard to get the thread to spin since rotating the filter just causes the glass element to spin around.

Also, I'd be careful with filter wrenches, they help get the filter loose by increasing the torque that you can apply relative to just a bare hand. Increased torque leads to increased chance of damaging the lens. If a filter is really so tightly stuck that the wrench doesn't EASILY get it loose I'd suggest other options before you start applying a lot of force to the wrench.

Ha, this B+W "wrench" its a tiny plastic thing, cannot cause any damage

I wholeheartedly agreed with all of the main points in this review. I've been using this exact model of filter for just over three years now. It very frequently gets stuck on my lens, especially with temperature swings. However, it also does its job beautifully.

I'll add one thing. I'm hard on gear (just clumsy). I've dropped my B+W CPL on numerous occasions, sometimes into water. Although it has picked up some tiny scratches, overall I'm very impressed with its longterm durability.

I just purchased a Breakthrough Photography X4 CPL in a different size. So I'll be curious to see how that one stacks up to the B+W version.

Kirk Darling's picture

An interesting omission on this filter (and I use this brand and model) is the lack of an index mark on the rotating edge. The index mark is supposed to indicate the point 90 degrees off the plane of polarization--you rotate the filter so that the index mark points toward the sun, and that's the maximum degree of polarization for the camera pointed in that direction.

In the case of that filter, the "index" point is where it says "B+W"--rotate the filter so that is pointed toward the sun, and the filter will be set at maximum polarization.

The missing mark is intentional. If you would PUSH the filter on the lens on a defined position (the rear foil horizontally perfect aligned with the sensor) the mark on front ring would make sense. When one screw the filter on whatever lens or adapter ring, no-one knows whats the position of rear foil against the sensor.

Kirk Darling's picture

One of us is not understanding the other. The filter rotates 360 degrees in the threaded ring. The index mark indicates the polarizing direction of the filter, which is at greatest effect 90 degrees from the sun. If you know what that direction is (by an index mark) you can always turn that mark toward the sun and immediately set the filter at its greatest point of effect.

Kirk, this 90 degrees mark is valid only in case that the rear foil is perfectly aligned with the sensor. When you screw the filter on lens nobody knows at what angle are the ribs of rear foil against the sensor, so you have 99,9% chance that the marking point is not valid.

Kirk Darling's picture

Except that I was shooting with one just yesterday and when I turned the "B+W" mark toward the sun--why, voila!--that WAS the point of greatest polarization. And it works every time. And some other filters, such as Hoya, do still have the index mark.

Light is polarized as it reflects from non-metallic surfaces in the scene. The polarizing filter removes light that has been polarized at a different orientation from the filter. All that happens before the light even enters the lens.

The significant factor is the orientation of the filter to the polarized light from the scene. The orientation of the sensor to the filter is irrelevant.

May the marks be with you.