Choosing the Perfect Lens Filters Is Down to Urth

Most self-respecting landscape photographers will have dabbled in the delights of using filters on their lenses. I’ve tried multiple brands with differing results but have always been more pleased with the photos when using Urth filters than any others. This review will guide you through what different filters do and why I rate them so highly.

The main reason I rave about Urth is the combination of the quality of the glass they use and the resulting optical performance. There's also the value for money and the good the business does for the planet. I have found that they give little or no degradation to the quality of the image and minimal color cast. I have bought other brands' filters that just didn’t hit the mark in comparison. Price-wise, they cost far less than many brands on the market. Plus, with every purchase, they plant trees and support small indigenous populations.

Urth introduced a kit of top-of-the-range Plus+ filters that fit magnetically to the lens. I’ve been testing these as well as the ND2-32 Plus+ variable filter to see if they still stood up to the expected standards.

The Magnetic Lens Filter Kits

I don’t know about you, but I have struggled with screw-on filters. Firstly, aligning the thread with that on the lens is a nuisance, especially when it's freezing and my fingers are numb with cold. Also, shooting in an environment where fine sand particles blow in the air, as I often do, can make attaching the filter problematic. Furthermore, screw-on filters do tend to lock together. I have the knack for releasing them and have rescued many colleagues who couldn't remove the filter from their lens, but I often feel a pang of panic when I first notice a filter's screw thread has locked.

Magnetic filters are advantageous as they snap onto and off the lens easily yet hold in place when in use.

The filters come in a stack with metal end caps, plus a screw-on magnetic adaptor ring; not all lenses are magnetic. The kit comprises a UV filter, an ND8, an ND1000, a CPL (circular polarizing) filter, plus a magnetic adapter ring for use if the lens is not magnetic.

The filters are low-profile with a very slim magnalium ring. They feel light but well-made. They are made from B270 SCHOTT optical glass with a 20-layer nano-coating for better sharpness, added protection, and easier cleaning.

What Each of the Filters Do and How They Performed

My tests were conducted outside using the magnetic filter kit and the variable ND filter. It was a very windy but mostly sunny day, although clouds passed in front of the sun. The temperature was hovering around freezing. I should emphasize here that these tests were not strictly scientific but real-world examples of using them in the type of conditions I often face. The light constantly changed, and even consecutive shots without a filter fitted brought slightly different results.

I fitted my OM System M.Zuiko 40-150mm F4 PRO lens to my OM-1 camera set the white balance to 5,300 Kelvin (K), and photographed in aperture priority at ISO 200 and f/8.

The following illustrative photos are unadjusted raw files as produced by DxO PhotoLab rendered using the DxO rendering for the OM-1.

The Urth UV Plus + Filter

I’ll start by describing the most controversial of the filters.

Some people get very hot under the collar about UV filters. Indeed, some low-quality filters will degrade an image. However, I have done multiple tests with the Urth filters and found no discernible difference in the photos with the filter on or off. Having previously scratched a lens's front element, I use one on most of my lenses, along with a lens hood. But if you choose not to use one, that is fine. The arguments for and against using a UV filter are old and tired, so don’t continue that in the comments.

Below are the same two photos cropped. There's no degradation of detail. Note, I focused on the lighthouse.

The UV Filter Plus+ is advertised as cutting ultraviolet light, sharpening your photos, and protecting your lens against scratches, water, dirt, and fingerprints. On this occasion, I could not notice any difference in sharpness, but it was a cold, clear day at sea level. I haven't tried it up a mountain on a hot and hazy day. However, after the shoot, the filters were covered in sea spray, so it did protect my lens.

The Urth ND 8 Plus + Filter

ND (neutral density) filters cut out some light coming through the lens, in the same way sunglasses reduce the light coming into your eyes. An ND8 filter only lets through 1/8th of the light—three stops. So, for example, if you had an initial shutter speed of 1/8 second, by adding the filter, the shutter speed would be lengthened to 1 second to achieve the same exposure. Starting from 1/1,000 second, the shutter speed would be reduced to 1/125.

The Urth ND 1000 Plus + Filter

Of all the filters I use, the ND1000 is the one I employ the most, often in conjunction with the Live ND built-in filters in my OM-1 camera.

The ND1000 filter cuts the light reaching the lens by 1/1,000—ten stops. So, if you had an initial shutter speed of 1/1,000 second, adding the filter will lengthen that to 1 second. A 1/500 second exposure would become 2 seconds, and a 1/250 second exposure would become 4 seconds, etc.

This was the only filter that resulted in a minuscule reduction in sharpness. That was to be expected, and I have not yet met a 10-stop filter that doesn’t reduce sharpness and micro-contrast to a greater or lesser extent. However, the difference was so small that I could only see it when zoomed in to 100% and compared side-by-side with an identical image shot without a filter. With some other filters, that difference is far more noticeable. Moreover, if pixel peeping is your thing and you need to zoom right in to notice the difference, it is fixable in raw development software.

When shooting a seascape, there seemed to be a slight blue cast, but again, the light was constantly changing, so see my white balance test results below.

The Urth Plus + CPL Filter

The fourth filter is a circular polarizing filter. Light, when it bounces off a surface, becomes polarized. In other words, instead of being random in direction, the waves of photons align in parallel. (This is a very simplified explanation.) The CPL filter can be rotated to stop the reflected light from different angles passing through. It also reduces the exposure by around a stop. Note that "circular" doesn’t refer to the physical shape of the filter but the filtration type.

CPL filters are useful for removing reflections off glass and water. Some use them to enhance color on a carpet of fallen autumnal leaves, and vehicle photographers employ them as well. These filters also cut some of the polarized light from the sky, resulting in deeper and more saturated blues.

Again, I found the resulting images sharp. The polarizing effect on the sky was more subtle, giving more realistic-looking results than some filters I have used.

The Urth Plus + Variable ND 2-32 Filter

Variable filters are popular with videographers. They are more versatile than fixed ND filters and allow the videographer to maintain a constant exposure in variable light without changing the shutter speed or aperture.

White Balance Tests

As mentioned above, the light varied considerably as clouds occluded the sun. So, at home, I set my grey card on a stand and illuminated it with a Neewer FS230B Bi-Color Monolight with the output set to 5,500 K. It's important to note that grey cards are not intended for white balance measurements and always have a color tint. Therefore, I didn't expect an identical white balance reading from my camera. I should, however, get a consistent set of measurements for comparison as I added each consecutive filter. To read the white balance, I opened the photos in PhotoLab 7.

• With no filter attached, the camera measured the white balance to be 6,035 K and +6 tint.
• With the CPL filter fitted, the white balance was 6,719 K and +6 tint.
• The ND1000 filter gave a reading of 7,755 K and +11 tint.
• The ND8 filter measurement was 6,894 K and +2 tint.
• The UV filter was 5,975 K and +4 tint.
• The Variable ND filter at either extreme, ND2 and ND32, gave 6,129 K and +14 tint.

Although there was some variation, even with the biggest increase in temperature using the ND1000, the variation was small and can be easily compensated for in raw development. This was far less variation than I have found with other filters. I haven't yet found any other filters that come as close to the original unfiltered result.

Bokeh Tests

Another test I do with filters is to aim the camera at a light source and then drop the camera out of focus. With a poor-quality filter, in the bokeh, it is possible to see either concentric or latitudinal lines running across the out-of-focus balls of light. This wasn’t apparent using any of the filters.

Easy to Use

In the field, the Urth magnetic filters were easy to change but sat securely enough not to fall off. I often shoot in a cold and windy environment, and today that was the case. The magnetic filters were easy enough to change despite my freezing-cold fingers.

The magnetic filters are slim enough to use in conjunction with a lens hood, but this is not the case with the screw-on variable filter. However, videographers would usually be using this filter and wanting to access it anyway. The wider profile of the variable filter gives more leverage, making it easier to remove than a standard screw-on filter.

These filters suit my minimalist approach to photography gear: a camera, maybe a tripod, and filters are all I take on a landscape shoot. The magnetic filters especially make this way of working even easier.

Environmental Factors

Some businesses in the industry pay lip service to environmental protection. Nevertheless, there is a small minority that does their bit to help protect the planet. One of the great things about Urth is its commitment to protecting the environment. They plant trees with every purchase; so far, they have planted 7,446,435.

Every Urth product purchased supports a community affected by deforestation to plant a tree. In collaboration with our tree planting partner, Eden Reforestation Projects, we've helped fund reforestation projects in Haiti, Indonesia, Madagascar, Mozambique, and Nepal. All of these projects provide employment and rejuvenate surrounding ecosystems for communities affected by deforestation.

Furthermore, Urth's packaging is plastic-free, and the paper and card are FSC-certified. They are also a member of 1% for the Planet.

What I Liked and What Could Be Improved

What I Liked

• Superb optical performance
• Excellent build quality
• Versatile range of filters to suit most photographers’ needs
• Easy to use
• Strong magnets prevent the filters from falling accidentally
• The Variable ND filter has stops at either end to prevent turning beyond the designed maximum and minimum adjustments
• Although more affordable than some of its competitors, the filters offer as good or even better performance
• Environmentally conscious company

What Could Be Improved Next Time?

• I am hard-pushed to find anything I don’t like about these filters.

In Conclusion

As the winter holiday season approaches and Black Friday is upon us, I can see these being an attractive proposition as presents for photographers. They really are a top-notch product; do look out for Black Friday special offers. Furthermore, the company’s dedication to giving back to the planet makes its filters a superb option for the environmentally conscious photographer.

The Urth Magnetic Essentials Plus+ lens filter kit and the Urth Variable ND filter retail price vary depending on the lens filter size, so make sure you buy the right size for your lens.