If you don’t have time to read the entire article, then the best variable ND filter is the PolarPro Variable ND Filter – Peter McKinnon Edition, thanks to it’s high build quality and excellent image quality, beating all competitors.
Variable ND filters are one of the most crucial pieces of photographic kit for videographers, and are also incredibly useful for photographers who don’t want to waste their time switching neutral density filters in changing light conditions.
They let you shoot wide open in bright light, create smooth motion blur on waterfalls or clouds, or just let you make high quality films in situations where you would otherwise blow out your highlights.
This article covers the best variable neutral density filters currently available, plus gives you an idea of how to choose the right one for you, and explains which pitfalls to look out for.
The Best Variable ND Filter
Best Variable Neutral Density Filter
Variable ND Filter Comparison Table
Quickly compare all of the top models of variable ND filters in the table below, then read the full reviews of each to see which would be best for you style of photography.
Variable ND Filter
2 - 5 Stops;
2 - 8 Stops
1 - 8.66 Stops
1 - 8.66 Stops
67mm, 77mm, 82mm
52mm, 58mm, 62mm, 67mm, 72mm, 77mm, 82mm
37mm, 40.5mm, 43mm, 46mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm, 86mm
37mm, 40.5mm, 43mm, 46mm, 49mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm
What is a Variable Neutral Density Filter?
A neutral density filter, or ND filter, are simply pieces of glass that cover the end of your camera lens to block out light, effectively making what the camera sees darker.
They can come in many forms, but here we are only concerned with variable neutral density (VND) filters.
Variable, or adjustable ND filters are found only as the circular type of filter, unlike solid ND filters, and consist of two circular polarizing filters stacked on top of each other. (A single polarizing filter on its own is a type of solid ND filter, although it reduces light by blocking certain polarizations, rather than by simply having a dark coating).
The inner filter is fixed, while the outer filter can be rotated. As the filter is rotated and the polarization planes diverge, the light being blocked increases by several stops. Most variable neutral density filters work over a 4 – 5 stop range (although many quote a range higher than is usable in practice).
As the amount of light blocked can be easily changed without covering the frame, a variable filter makes the best ND filter for video recordings.
How Do You Tell VND Filters Apart?
Variable ND filters have a series of numbers on them that refer to both how much light they block and the size of lens that they can be affixed to.
The above image is a typical ND filter with some info that you can ignore, such as the brand and model name (B+W 103), and some more useful info.
The most important information is next to the ND label, showing that the filter can have a neutral density effect of 0.9, which is equivalent to 3 stops of light that this filter can block.
The 72 in the image refers to the thread size of 72mm, a common thread size for wide angle lenses. You can find the thread size of your lens written on the lens next to a circle with a line through it. In the lens shown below, the thread size is 77mm.
As variable ND filters must be screwed onto the end of your lens, they must match the size of the lens, meaning that if you want to use a variable ND filter on multiple lenses of different sizes, you will need multiple VND filters – one for each differently sized lens.
Because you must match the lens thread size to the size of the filter, you will most commonly see 77mm neutral density filters, as most wide angle lenses have this thread size. If you get the size that matches your largest lens, then you can always use step up rings to attach smaller lenses onto the larger filters, meaning that lens thread size becomes less of an issue.
Why Should You Use a Variable ND Filter?
Variable neutral density filters are particularly useful for videographers, as they allow you to change the amount of light blocked while still filming. If you used solid filters, you would have to stop filming, unscrew the filter and screw on a new one to get the same effect.
They are also very useful for photographers for the same reason – they mean much less wasted time when out taking photos and allow you to deal with changing light conditions with ease.
ND filters overall give you much greater range for your photography, letting you balance lighting and create motion blur. Specific uses include:
- If you want to shoot long exposure photos of waterfalls, clouds and similar.
- If you want a set of filters for landscape photography for sunsets and to balance the exposure across the scene.
- If you want to shoot photos at wide apertures (Eg. f/2.8 or wider) in bright lighting.
- If you want to create videos of street scenes.
Because videographers need high shutter speeds to shoot their videos, variable ND filters are crucial to preserve details in bright scenes, including outdoors in sunshine, or even at night in bright streetlighting.
What ND Filter Value Should You Use?
If you are a photographer looking to create motion blur, then you will need the largest amount of light blocking that you can afford, usually up to ND10, while a videographer can probably get away with an ND3 – 4 for most day-to-day uses.
Or you can use the ND filter chart below to get a feel for what density of filter you will need for your style of photography or videography. Find an appropriate neutral density filter on the left, then use the ND filter calculator to see the shutter speed you will need based on the shutter speed without using a filter. This assumes that the aperture and ISO remains the same.
What Makes the Best Variable ND Filter?
Cheaper variable ND filters can be susceptible to problems, such as light leaks, white balance shifts or cross-hatching at their extreme ends. They are also often made from plastic rather than aluminum.
White balance issues can often be quickly fixed in Lightroom, so are less of a problem if the color shift is consistent across the frame. See the example below for the before and after fixing this color shift.
Cross-hatching is a much greater issue, and shows an “X” pattern once the filter is pushed too far. PolarPro avoid this by having hard stops in their filters.
In the photo below, you can see that the effects of the variable ND filter are not consistent across the frame. This is likely because of cross polarization caused by using a wide angles lens. As the polarization of light changes with respect to its position relative to the sun, and because a wide angle lens covers such a wide area, the light will be polarized in different planes across the frame causing patches of light and dark.
But this could also be caused be the polarization planes being tilted with respect to one another, or even light leaking in-between the two glass elements in the filter.
This is why it pays to get a better quality variable ND filter.
While the top models are quite pricy, being in the $150 – $200 range, they do offer far superior performance, and are likely to last you for years.
Variable ND Filters: My Reviews
Best 77mm Variable ND Filter
- Image quality as good as shooting without a filter
- No vignetting down to 16 mm focal lengths
- Clear markings and hard stops so you can see level the filter is set at
- No cross-polarization
- Best Variable ND Filter 77mm
This PolarPro variable ND filter is an outstanding example of a variable ND filter, with no effects on image quality, sharpness or color. Unlike with some cheaper models of variable filter, there is no cross-polarization issues, where you get patches of light and dark, no matter whether the filter is pointing at the sun or not.
This filter comes in two flavors – 2 to 5 stops, which is the best Variable ND filter for video as it is really designed for the run and gun approach, and 6 to 9 stops, which is more expensive, but better suited for really bright conditions.
You get hard stops with the PolarPro, meaning that you can’t push the filter beyond its recommended limits, and the markings on the outside mean that you are always aware of how much f-stop reduction you are applying. Other than price, there is nothing to not recommend the PolarPro for videographers, although photographers might find better value for money in a square ND filter set.
Tiffen 77mm Variable Neutral Density Filter
- Good value for money
- Available for 52 mm – 82 mm lens threads
- Filter position markings are not numbered
- Some users report cross-polarization
The Tiffen variable ND filters actually offer some of the best value for money for variable filters, and are significantly cheaper than the PolarPro model reviewed above. They are significantly wider than the lens they are attached to, which helps prevent vignetting and also means they are easy to grab hold of and change the f-stop reduction.
Build quality does seem to vary, as some people get filters with scuffs and scratches, while others get pristine models. Also, there is a good chance that you will see some cross-polarization at the most extreme ends of the filter. This is exacerbated by there not being any hard stops on this filter, so it is easy to push this over the edge where you will see a dramatic drop-off in image quality.
Still, if you are starting out with variable ND filters, and / or are making non-professional videos, then the Tiffen will generally serve you well.
Best Budget Variable ND Filter
- One of the cheapest variable ND filters that still offers good performance
- Available in 37 mm to 86 mm
- No appreciable color cast, and little negative effect on image quality
- Markings on the ring are not clear
- No hard stops
- Threads can get ‘sticky’ when trying to take the filter off
Gobe variable ND filters (now called Urth) offer good performance at one of the lowest prices for variable filters. They are designed to offer from 1 stop to 8.66 stops of light reduction, but you will see less than this in practice due to cross-polarization. As there are no hard stops, you will see X lines in your images if you accidentally push the filter past its recommended settings, which can ruin any video footage, but is less of a problem for photography.
The Gobe has high build quality, feeling solid in the hand and comes with premium packaging that makes it feel as though care has been taken with its design. Overall, I would consider this the best budget variable ND filter over the K&F model reviewed below, as this feels like it has been manufactured to a higher quality level, and so this is an excellent variable ND filter for those who are more price conscious.
Variable Neutral Density Filter Review
- Very low price
- Highly rated by amateur photographers
- Excellent entry point to variable filters
- Only about 4 usable stops of light reduction
- Relatively strong color cast and some softness
As a cheaper alternative to the B W variable ND filter, the K&F is a great starting point if you are not sure whether variable ND filters are for you or not. It’s performance is of course not up to the same level as the PolarPro or other premium models, but at about 1/10th of the price, you would not expect this.
In fact, the optical ability is not at all bad, although you are only getting about 4 usable stops from the filter, and do not have a hard stop at the min and max ends. There is also some ghosting and lens flare present when shooting into the sun, but this should be expected at this price.
Final Thoughts: Which Variable ND Filter is Right for You?
I hope you can see from the reviews above that there is quite a range of prices and quality in variable ND filters. Although my recommendation would be to choose the highest quality filter, like one of the PolarPro’s, this isn’t always possible for budget reasons.
In that case, even the cheaper filters like the Urth will be good enough, although bear in mind that picture quality will likely be lower than the PolarPro, depending on your camera and lens combination.
And don’t forget that if you want a really high quality filter, but don’t want to pay variable ND filter prices, then there are many solid ND filters of the same high quality, that are available at a fraction of the price. Read my article on the best ND filters for more.