The best variable ND filters make ideal companions for videographers, filmmakers and photographers alike. Giving you incredible flexibility in controlling the amount of light that enters a lens, variable neutral density filters can be adjusted to different levels of opacity, meaning you can block a lot of light, or relatively little, all with the same filter.
A variable ND filter enables you to can slow down the shutter speed to create amazing long-exposure effects. These include creating milky seas and skies, erasing moving people from an urban scene and creating dramatic light trails.
This can be done with the best neutral density filters too, and will give you better image quality. However, those filters aren't adjustable. If you've got a 10-stop filter mounted to your lens, and you want only eight stops of light reduction, you've no choice but to change filters (assuming you even have an eight-stop filter), which takes time and necessitates carrying around a lot of fragile glass.
Variable ND filters keep your kit light, and reduce your chances of missing the shot. Variable NDs also have plenty of applications for videographers, who have fewer options for varying and controlling exposure since they're usually using a fixed shutter speed.
As long as you know what you're getting into, variable ND filters can be a tremendously useful tool. Here are, for our money, the best variable ND filters you can buy right now.
Ben Andrews
Ben is the Imaging Labs manager, responsible for all the testing on Digital Camera World and across the entire photography portfolio at Future. Whether he's in the lab testing the sharpness of new lenses, the resolution of the latest image sensors, the zoom range of monster bridge cameras or even the latest camera phones, Ben is our go-to guy for technical insight.
It’s a low-cost filter, but it’s still well-made, with a smooth rotation action, clear markings of the range, and a textured edge for easy grip. Read more below…
6. PolarPro Variable ND Peter McKinnon Edition 2-5EV
Some variable NDs generate vignetting when they’re used on wide-angle lenses, but this filter positively embraces a wide field of view. Read more below…
Best variable ND filters in 2024
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With a generous range of ND3 to ND 400, the second generation of Hoya’s variable ND is a class act. It’s simple to use, with markings on the front and rear frames so you know how far along the scale you are as you rotate an element. There’s a discrete knob to handle rotation, avoiding the risk of fingerprints.
We were delighted with the results we got from the Variable Density II when we had it in for testing. There was barely any impact on sharpness, color or contrast as we boosted the ND factor. There were some examples of cross-polarization (X-shaped dark areas in the image) – but only when we pushed beyond the parameters of what we’d expect to be normal use.
Hama’s slimline variable ND filter is well made for the price, with a smooth rotation between the two elements and just enough friction to hold its position when set. A slight textured edge to the front element makes adjustment easy, and there are clear markings between the minimum and maximum points.
At the minimum setting the filter enables you to lengthen the exposure by one stop, and influences color with a slight coolness. We found that increasing the intensity to the maximum marked setting produces a heavy black X, but pull back a little and you can extend exposure times by almost eight stops (although images do need retouching to remove the color cast). A setting of around five stops gives the cleanest results.
Hama claims the filter is coated, but gives little detail of the benefits. They certainly don’t include moisture or fingerprint resistance, as the filter attracts both. It’s also a pity you can’t get the Vario in an 82mm diameter.
This is one pricey screw-in filter – but maker Schneider Optics claims it’s a cut above the competition thanks to a Multi Resistant Coating. Where an uncoated filter can reflect around 4% of light, this one only reflects 0.5%, while also minimizing ghosting and reflections, and repelling water droplets.
The filter is 9mm deep, not including the thread, with knurling around the fixed ring that makes it a doddle to fit and unscrew. The rotating front ring has hard stops to mark the minimum and maximum filter densities, but markings in-between don’t correspond to f-stop light reduction amounts. Rotation is smooth, with pleasing resistance.
The filter is specced to provide between one and five stops of light reduction, which we found to be accurate – but expect uneven light transfer beyond around three stops of reduction. Filter neutrality is good, though – image quality is exceptional, with little or no color cast evident, and there’s good tone and contrast throughout the image.
There aren't a lot of regular surprises in the world of photographic filters, but H&Y's Revoring system is one. This clever device is two filters in one – both a polarizer and a variable ND filter – and what's more, its spring-loaded attachment mechanism means it can adapt to a huge range of filter sizes.
In use, the two filters rotate independently via small metal lugs. You rotate the rear filter and front filter together for the polarizing effect, and turn the front filter relative to the rear to apply the variable ND effect. As we discovered in our review, the system works extremely well once you get used to it. The top-tier quality of the glass in the filter helps, ensuring excellent image quality.
Not everyone will find it useful to have a polarizer and variable ND in the same kit. But for those who do, the H&Y Revoring is a no-brainer.
The best variable ND filter for flawless colour neutrality
Specifications
Sizes available: 67mm, 82mm
Exposure increase: +1 to +8.5 stops
Reasons to buy
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Accessory rings
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Flawless optical performance
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Quality build and presentation
Reasons to avoid
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Big on small lenses
Syrp likes to do things a bit differently: even its humble variable ND filter gets a unique treatment. It comes packaged in a classy cylindrical cardboard outer carton; the filter gets a round, leather-wrapped zippered storage pouch.
Instead of the usual range of multiple filter sizes, there are only two core versions of the Syrp filter: a 67mm and an 82mm. The former comes in the Small kit option, which includes adapter rings to mount the filter to 58mm and 52mm lenses, while the 82mm Large kit contains 77mm and 72mm adapters.
Syrp’s fancy packaging isn’t a case of style over substance, though. We found the filter’s neutrality to be exceptional, with no color casts evident. The ND2-ND400 range also contains an impressive four-stop band that delivers no visible exposure inconsistency. Factor in the water and dirt-resistant front coating, and you’ve got one fabulous filter.
(Image credit: Angela Nicholson/Digital Camera World)
6. PolarPro Variable ND Peter McKinnon Edition 2-5EV
Great choice for wide-angle landscapes
Specifications
Sizes available: 67, 77, 82, 95mm
Exposure increase: 2-5 stops
Reasons to buy
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Designed for use with wide-angle lenses
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Great quality
Reasons to avoid
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Slightly warm tone
The trouble with some variable ND filters is that they create serious vignetting and cross-polarizing artifacts when they’re used with wide-angle lenses. The PolarPro Variable ND Peter McKinnon Edition 2-5EV filter, however, is designed for use with even a 16mm full-frame focal length. It keeps vignetting under control very well and the filtration level adjustment stops before the notorious cross-effect becomes visible. A separate 6-9 stop version is also available.
If you’re shooting a clear blue sky with a wide-angle lens and 5EV filtration, you’re likely to see some variation in tone, but it’s not bad. In addition, the filter has a very slight warming effect, but it’s not unpleasant. If you’re shooting scenes with lots of detail you’re unlikely to notice any flaws, and you’ll appreciate the ease of exposure control.
A variable neutral density filter is essentially two polarizers fixed together to form one screw-on filter. When you rotate these two filters against each other, the elements restrict the amount of light that's able to pass through. It's worth noting that if a variable ND filter is rotated too far, it will tend to produce a darkened X effect, which will appear on your image. This is often referred to as 'crossfade'. It's pretty much ubiquitous on ND filters, so it’s just something you need to watch for rather than a faulty product.
What do strength ratings like ND2 and ND4 mean?
The ND strength ratings quoted for ND filters correlate with adjustments to your exposure. ND2 is equivalent to a 1 f-stop reduction to the exposure. When an ND rating doubles, that’s equivalent to a further f-stop reduction – so ND4 is a 2 f-stop reduction, ND8 is a 3 f-stop reduction, and so on.
A typical range for a variable ND filter is ND2 to ND400, which means you can adjust it to make anything from a 1-stop reduction to a little over eight stops.
How to convert an ND strength rating into f-stop and shutter speed reductions. Tap the symbol at top-right to view full-screen
When we test filters, we look at both optical performance and general build quality – how robust the filter feels, how easy it is to use and how securely it attaches to the lens. We use a combination of real-world and lens testing to inform our comments in reviews and buying guides. For filters, we test light transmission levels, colour neutrality (i.e. if the filter introduces a cool or warm cast) and the impact a filter has on image quality.
We also look at any specific known issues with different kinds of filters – so for variable NDs, we look out for the infamous 'crossfade' effect, which is the X-shaped pattern these filters are known to produce.
Ben is the Imaging Labs manager, responsible for all the testing on Digital Camera World and across the entire photography portfolio at Future. Whether he's in the lab testing the sharpness of new lenses, the resolution of the latest image sensors, the zoom range of monster bridge cameras or even the latest camera phones, Ben is our go-to guy for technical insight. He's also the team's man-at-arms when it comes to camera bags, filters, memory cards, and all manner of camera accessories – his lab is a bit like the Batcave of photography! With years of experience trialling and testing kit, he's a human encyclopedia of benchmarks when it comes to recommending the best buys.
