Kase Wolverine 100x150mm Double Grad: At a glance

  • 100 x 150 x 2 mm
  • Two graduated ND filters in one
  • Tempered mineral glass
  • Protective case included
  • www.kasefilters.com

This is one of those ideas that at first sight you think can’t possibly work, because otherwise everybody would be doing it. Landscape photographers use neutral density graduated filters to balance bright skies against dark foregrounds, with 100mm-wide filters often the preferred size to minimise any risk of vignetting with wideangle lenses. These filters usually measure 100x150mm, but at any given time, most of the glass isn’t being used. So Kase has realised that it can make two filters on one piece of glass.

The Kase Double Grad in position on the Kase K9 filter holder

Rather than simply fading from neutral density at one end to clear at the other, Kase’s new double grads are split into thirds, with a clear centre and ND sections at each end. The two grads are labelled so you can tell them apart, although with small lettering just 2mm high. My review sample had 3-stop hard and soft gradations, with the first providing an abrupt transition that’s ideal for straight horizons such as seascapes, and the other with a more subtle fade that works better for more complex scenes. The idea is that you can choose between the two simply by spinning your filter holder through 180°.

Kase Wolverine Double Grad: Key Features

  • Versions  As well as the hard/soft double grad shown here, a medium/reverse option filter is also available
  • Case  Kase supplies the filter in a slimline protective faux-leather case that won’t take up excessive space in your bag
  • Money saving  The double grad saves more than £80 compared to buying an equivalent pair of filters separately
  • Robust  The double grad is made from the same scratch-resistant toughened optical glass as Kase’s regular filters

Shot using the hard grad. Sony Alpha 7 III, FE 16-35mm F4 ZA at 16mm, 1/60sec at f/11, ISO 200

So does it work? I tested the double grad using a wide range of focal lengths and a variety of holders of different makes. To cut a long story short, for the vast majority of the time it works just fine. You can eventually run out of glass in the most extreme situations, for example when shooting with lenses of 16mm or wider, in portrait format, with an angled horizon either high or low in the frame. For me that’s a niche scenario, but for others it could be a legitimate concern.

Turn the camera to portrait format with an ultra-wide lens, and you can run out of room to adjust the filter. Sony A7 II, 16-35mm F4 ZA at 16mm, 1/40sec at f/1.. ISO 100

Another niggle comes with horizons in the bottom half of the frame, for which the filter must be placed very low down in the holder, as shown on the right. This makes it more awkward to adjust accurately, as you have to manipulate it from beneath the camera. It also raises concerns over light leakage and flare, but these are perhaps more theoretical than practical. There’s nothing to complain about regarding the quality of the glass, though; the filters are perfectly neutral and have no perceptible impact on detail.

Kase Wolverine Double Grad: Compatibility

At 2mm thick, Kase’s double grad filter should fit most brands’ holders. I tested it using Kase K9, NiSi V6 and Formatt Hitech Firecrest holders, without any problems. However I’m not convinced it would work properly with Benro’s geared FH100M2 and FH100M3 systems, which require filters to be held in plastic frames.

Kase Wolverine Double Grad: Our Verdict

Kase’s double grads turn out to be an ingenious concept with surprisingly few snags. Photographers who routinely shoot at very wide angles should probably stick with conventional filters, but for other users they could save both money and space.