Variable neutral density filters have become invaluable tools for many photographers and filmmakers. They allow us to carry less kit to be able to extend our shutter speed in a variety of lighting conditions vs big holders and multiple square format filters. In recent years, their prices have fallen quite dramatically, too, while their overall quality has greatly improved.
Moment’s recently released variable ND filters have come in at a very attractive price, but do they hold up to scrutiny? With the lockdown in Scotland, I haven’t been able to get out to play with them properly in the wild yet, but I have been able to do some testing to get an idea of their capabilities. So, here’s what I think.
First impressions & use
The Moment variable ND filters were initially released in 67mm, 77mm and 82mm diameters. As of today, though, they’re available in more sizes including 58mm, 62mm and 72mm. The ones I’ve been using are 77mm, as this is the largest filter diameter of the lenses I own. For smaller filter diameter lenses, I use inexpensive step-up rings. It saves bag space and cost by not having to have multiple sizes of the same filters.
The filters each come in an attractive metal protective case that’s not much bigger than the filter itself. They’re round, like the filters, and lined inside with foam on both the top and bottom halves. The top of the case screws onto the bottom, similar to how the filters themselves screw onto the end of a lens. On opening the case, we see the filter inside, along with a small cleaning cloth which is very good at pulling off fingerprint grease (don’t ask me how I know).
The filters themselves are wider overall than other filters of the same thread diameter due to the unique design of the rotating front end. It’s an interesting design that allows you to see the intensity setting while standing behind the camera (rather than from above or to the side) and a design that many people will find useful. That being said, it does mean you likely won’t be able to use a lens hood, which could be a deal-breaker for some.
Like many other variable ND filters on the market today, the Moment filters have hard stops with a limited range of a few stops. In this case, ND4-32 (2- 5 stops) and ND64-512 (6-9 stops). This is to help prevent the cross-polarization issues you often see with extreme and lower-end variable ND filters that offer up to 7 or 8 stops of range, resulting in that dreaded X pattern across your shots. This cross-polarisation is due to the fact that variable ND filters are essentially just two polarising filters sandwiched together.
Most variable ND filters have the markings on the side of the filter, whereas the flanged design of the Moment variable ND filters allows you to easily see the strength setting of the filter while standing behind the camera with easy to read markings at one-stop intervals. This can be very handy when you can’t easily get above or to the side of a lens to see the markings. But as you’ll find out a little later, it’s not always a benefit.
As I said earlier, there’s a lockdown in place here in Scotland at the moment. This means it’s virtually impossible to get out and test these in the array of real-world scenarios I would have liked, so the back yard turned out to be my destination of choice for initially trying them out.
While it’s not quite the same as heading out into the middle of nowhere with gorgeous landscapes, it can still serve to give an idea of how easy they are to put on, take off and work with in a somewhat real-life environment (even if only simulated). I went out with just the camera and the two filters in their metal cases in my pockets as if I were going out to shoot on location. The photos weren’t anything to write home about and certainly nothing that would actually benefit from the addition of neutral density filters, hence there not really being any of them in this review.
Although the small size of the cases is fantastic for portability, they can be a bit fiddly to use compared to the magnetic flip cases found with some other filters, especially if one of your hands is full holding a camera.
You need both hands to be able to open the case because one needs to hold the bottom while you unscrew the top. Which means your camera needs to be set down on the floor or a tripod or swinging off your shoulder with a strap. The process goes a little something like this…
- Put the camera down somewhere safe
- Open up the case with the filter inside it using both hands
- Put the top of the case down somewhere so you can remove the filter from the case
- Put the bottom of the case down somewhere so you can pick up the camera and put the filter on in
- Put the camera back down and pick up the two halves of the case
- Screw the two halves of the case together and put it back in your pocket
- Pick the camera up and start shooting
Fortunately, the weather is great here right now, so it wasn’t too much of a hassle, but I can imagine that in colder temperatures where you might find many of the more dramatic landscapes where you’d want to use a neutral density, it could be frustrating having to deal with a case that you need to screw on and off – especially if wearing gloves. And if you’re off in the middle of nowhere with ground that isn’t suitable for putting items down on, then you’re going to be a little stuck.
So, as much as I like the idea of the metal cases for general protection, I think a magnetic flip case or a padded soft case would be more practical for use out on location – where you’re most likely to actually need and use variable ND filters. Of course, if you know you’re only going to be using a specific filter the whole time, you can always attach it before you head out so you don’t have to worry about it.
Thanks to the design and extra width of the front of the filters, they screwed onto the lenses very easily. More easily than most variable NDs I’ve used, where it’s easy to slip or catch your fingers on the end of the lens itself while screwing it on. I’ve dropped a few filters over the years because my fingers ended up grabbing the end of the lens while screwing it on and losing my grip on the filter.
The wider front on the Moment variable ND filters meant that being able to hold the filter clear of the lens diameter allowed for an easier hold to more easily align the two, minimising the risk of cross-threading, and screw it on for a snug fit.
With the filter on the lens, it was nice being able to see the intensity setting while staying in the same spot behind the camera, although it’s not a perfect system. It ended up being upside down or in an otherwise awkward-to-see position when screwed onto some lenses, which meant it was a little difficult to see the strength setting sometimes.
This isn’t an issue that’s unique to Moment lenses, but not being as easy to view from the side did feel like a little bit of a disadvantage at times. Perhaps this could be solved in a future revision of the filter by just printing the rear scale in more places around the filter. Say, repeated every 120 degrees. That way, no matter what orientation the filter ended up at, there’d be a scale somewhere around the top of the lens.
One thing I do like about the Moment Variable NDs is that even though it has a wider edge on the front, there’s still a lip in there that allows you to pop your lens cap on when you want to cover it up. Being able to quickly cover it up in the field was a big concern when I initially saw the design of these filters, but the lens cap holds quite firmly. Actually, it holds more firmly than other filters I have with a standard 77mm front thread. Also, because the cap isn’t protruding out as much from the end of the lens due to the design of the filter, it’s probably less likely to get bumped and fall off in a bag or while wandering around.
Overall, it wasn’t that much different from using any other variable ND, except for the upside-down orientation issue I mentioned making it difficult to see the number sometimes. For photographers, this may be a pain, but if you’re shooting video, then you’re probably relying more on your monitor scopes than the actual setting shown on the dial anyway.
Sharpness is an important one for all filters, not just variable NDs, so I’m going to tackle this one first. Being made from Schott B270 Pro Cinema Glass, I had pretty high expectations here, and they didn’t really disappoint at all. I’m doing these tests indoors lit by a continuous 5600K LED panel with a CRI and TLCI of 97 for consistency between shots.
Note: You can see the polarising effect of variable NDs in some of these test images, as the light bouncing off the desktop surface changes between shots. This is just the nature of all variable ND filters (polarisers, remember?), although it is something to be aware of when using them.
First up, here’s an image of the Datacolor SpyderCHECKR colour chart with no filter on the lens at all.
Here, I’ve cropped into a 100% section in the centre.
Next, four 100% crops from the centre using the 2-5 stop filter at 2, 3, 4 and 5 stops. The white balance and exposure of each of these shots has been set individually for each image to more easily see the difference in detail.
Now, the 6-9 stop filter. Again, 100% crops from the centre at 6, 7, 8 and 9 stops of strength.
As you can see, we do lose a tiny bit of sharpness by adding the filter, although it’s not a great deal at all. Sure, you can spot a little softness zoomed in to 100% with high resolution stills, but when viewing the image as a whole – as most people do – or when shooting video, there’s not really any noticeable difference in sharpness at all. Interestingly, the 6-9 stop variable ND filter actually seems a little sharper than the 2-5 stop, despite being much stronger, although both are very impressive.
So, the filters come in two flavours with 2-5 stop and 6-9 stop ranges. But how precise are those stop measurements? Especially with really long exposures? In this test, I swapped to the X-Rite ColorChecker Video to get some nice solid black, white and grey blocks of colour for easy viewing on the histogram.
The first image shows the baseline exposure of the scene. I’ve corrected the white balance on each of these images individually using the grey swatches so that we can just focus on the exposure variance between the shots.
Here are four images with the 2-5 stop filter at what the dial says are full-stop increments. The ISO and aperture on the camera remained the same, and the shutter speed was adjusted to compensate.
I ran the test again using the 6-9 stop filter at full-stop increments to produce four more images.
The exposure does differ a little bit between shots, although really not by massive amounts except for the brightest extreme of the 2-5 stop filter and the darkest extreme of the 6-9 stop filter. After matching the white balance of the brighter grey swatch, I compared the histograms of each and noted how much exposure compensation I had to add or subtract to make each stop match up where it was supposed to be. I’ve written this note under each shot above.
The result was not entirely unexpected. Variable ND filters rarely hit those one-stop increments exactly, and the fact that most of them were so close is very impressive. The differences between what we expected and what we got can easily be compensated for in post with minimum detrimental effect. It’s certainly no more of a problem than other variable ND filters I’ve used in the past and actually performs better than most of the ones I’ve tried in this respect.
Vignetting seems like pretty much a non-issue, too, other than the odd bit of polarisation you’d see with a regular CPL on certain focal lengths. This is likely in large part due to the wider front ring of the filter not blocking the incoming light that you often experience with stackable filters.
This test actually uses the same images from above. This time, however, I’ve matched the exposure of each shot in Adobe Camera Raw using the compensation adjustments noted above, and the white balance of all images is set to that of the unfiltered photo (5300K with a +4 tint) so that we can just look at the colour difference. As these are the same set of images, our unfiltered control image is the same as the shot above.
Again, the first set of four images uses the 2-5 stop filter, in full-stop increments. Remember, I’ve adjusted the exposure in raw processing to match each other but left the white balance alone to be able to focus on just the colour. For each thumbnail, I’ve noted what the white balance should be to give the correct colour.
And finally the second set of images using the 6-9 stop filter, again one stop apart.
The filters aren’t as neutral as using no filter at all. They run a little cool on temperature and towards magenta on the tint. The good news is, though, that they’re pretty consistent throughout their range of intensity. You can see from the exposure tests further up that it’s easy enough to correct your white balance in post to correct this, especially if you’re shooting raw.
If you’re shooting baked-in-colour non-raw video and have lots of shots to match, it might be a little trickier, but it’s not impossible. And if you’re using an external monitor with a vectorscope, then it’s easy enough to adjust your colour in-camera before you hit record.
Are the Moment Variable ND filters perfect? Well, no. But no variable ND filter is ideal for every situation. If you need specific control over your polarisation or you’re using extremely wide-angle lenses, then you may still be better off with fixed ND filters. Variable NDs are a compromise in situational ability vs efficiency, camera bag space and price. Spinning a dial on a variable ND filter is a lot less hassle than having to swap out an entire filter to change the value of ND over your lens, although they’re not always going to be as predictable as a set of fixed ND filters (or as expensive).
But on that compromise, Moment definitely should see these filters as a victory. They’re as easily good as other (and much more expensive) variable ND filters I’ve tried over the last couple of years and in some respects even better – when the intensity indicator lines up in an easy-to-see spot on the end of the lens. And if variable NDs give you what you need, then Moment offers a lot of quality for your money.
While the wider edge of the Moment Variable NDs will be a wonderful thing for some users for ease of use, it will be a hindrance for others, particularly those who wish to use hoods on their lenses along with the VND, as the hood will no longer fit onto most lenses if the opening is narrower than the outer diameter of the filter (which will almost always be the case). But this is ultimately going to boil down to personal preference and need.
- The rear-view of the strength setting is fantastic (when the filter lines up well) to be able to quickly see and adjust the intensity.
- The inclusion of a cleaning cloth that fits inside the case is a thoughtful touch (and it’s a good one, too).
- Being able to still attach a lens cap onto the filter (something I didn’t actually expect with their shape).
- The price – There are comparable quality variable ND filters on the market today that cost twice as much (or more) as these.
- Build quality – They feel well built and the adjustment ring rotates smoothly but firmly.
- The rear-view intensity indicator sometimes ends up in difficult-to-see places.
- Those screw-fit cases, while attractive, aren’t as practical on location compared to flip cases of soft pouches, especially if it gets cold and you’re wearing gloves.
- Using lens hoods becomes difficult or impossible.
Overall, they’re excellent value for what they cost. If you don’t need to use lens hoods and you want that run & gun efficiency of being able to quickly change the amount of ND over your lens at a moment’s notice, then they’re a fantastic option. I would suggest picking up some kind of easy access padded filter case, though, rather than taking the supplied metal cases out with you – especially if you plan to get both filters and have others that you wish to carry with you. Maybe this is something Moment will offer themselves if they expand their DSLR & mirrorless filter lineup in the future.