To kick off this review, I’d first like to provide a quick lesson about ND filters. Basically, an ND filter acts like tinted sunglasses for your lens. They dim the amount of light that comes in, so you can open up your aperture when shooting in bright sunlight. Shooting with a maxed out f-stop in a bright environment lets you achieve creamy, blurred backgrounds by selectively focusing on your subject. You can also shoot longer exposures than you would have otherwise. Without the tinted filter in front of your lens, employing these techniques would leave you with overexposed images. That’s why ND filters are a great creative tool for both video and stills.
Like sunglasses, ND filters are available in different shades of darkness. The darkest ND filters enable you to max out the aperture on fast lenses in direct sunlight. However, when the sun suddenly darts behind butts and you lose a lot of light, you may not be able to get a proper exposure without jacking up your ISO.
That’s one of the reasons why “variable” ND filters exist. They feature two filters, and they can be turned, which makes the darkness of the tint either intensify or decrease. You can instantly dial in exactly how much tint you need at any given moment. I’m not sure how this darkening and lightening of the filter is achieved, but it’s a pretty neat trick. It’s really cool to turn the ring and watch the filter transform from dark sunglasses to lightly tinted shades.
Another thing that ND filters have in common with sunglasses is that the really good ones are expensive. Before I purchased my variable ND, I did a lot of research, and not surprisingly, it turned out that there are good ones available at reasonable prices, but the best are considerably more expensive. If you vowed never to skimp on optics, one of the best options is the Singh-Ray Vari-ND.
What does “the best” get you in this case? From my research, the Singh-Ray is the least likely to exhibit vignetting when ultra-wide lenses are used, and more importantly, it provides the most natural color. The cheaper you go with variable ND filters, the more of a “color shift” you can get. In the worst cases, you can end up with a greenish tint in your images. However, for the most part, these differences are subtleties, and often only picked out by really discerning eyeballs. But, the differences are real. Fine glass in photographic equipment doesn’t earn a reputation for itself with smoke and mirrors.
Keep in mind that the majority of ND filters that are available aren’t variable. Instead of twisting to provide various shades, they’re just regular, fixed-intensity filters. They come in a ring style that screws onto the end of your lens, but they also come as square sheets of glass to use in matte boxes.
A standard ND provides better performance than a variable one, especially when you buy a good brand with precision glass. However, the standard ones aren’t versatile, and buying a single variable ND is equal to buying a large set of standard ND filters.
So, when choosing a variable ND, you are faced with a choice: go with the best, or get a slightly compromised budget-friendly option. The two most popular, non-cost prohibitive options are the Light Craft Workshop Fader ND and the Genus Fader ND. Lots of talented people use these two variable ND’s to great effect. However, I personally decided to splurge on the variable ND that had garnered the most praise, the Singh-Ray.
Another high-end option is the Heliopan Variable Gray ND Filter, and it’s actually a wee bit more expensive than the Singh-Ray. However, in my extensive pre-purchase research, I found more universal praise for the Singh-Ray, so that’s what I bought.
So why did I spend the big bucks when I’m not a professional? In my situation, I had a good camera body, and three good lenses. So far, that’s a pure pathway for optimum imagery. By adding a slightly weak link to that chain, I would be giving up optimal performance. I decided to get the best quality variable ND in a large size, 77mm, so I could adapt it to any sized lens. This way I would only have to pay for an ND filter once in my life, and I would achieve optimum image quality, no matter what camera system I used. It’s the old mantra: buy once, cry once.
So, what’s it like to actually use the Singh-Ray Vari-ND? The interesting thing is that it adds another control to your camera. I mainly shoot in Manual Mode, so I’m used to adjusting the aperture, ISO, and shutter speed as I go. Having the Vari-ND on the end of your lens is kind of like having a second aperture ring to adjust. It also kind of reminds me of the “Brightness” slider in Photoshop. Turn it this way and it gets brighter, the other way and it gets darker. The ring feels nice and turns very smoothly.
For the sake of supplying technical info, the Vari-ND supplies 2 to 8 stops of added density. Having the ability to quickly dial in what you want is really useful, and it’s not just for when your light changes. I was shooting pictures of my family when we visited a beautiful lake. It was great to capture portraits in bright sunlight with maxed out f-stops and blurred backgrounds, but it was also great to switch things up. I found myself alternating between having the aperture fully open with the Vari-ND set to Max, and then changing to a lower setting and decreasing the aperture size so I could get shots where you could clearly see the beautiful lake in the background. Having the ability to quickly take both kinds of photos was great.
Something to keep in mind is that you shouldn’t use other filters in conjunction with the Vari-ND, so take your UV filter off before use. Another important thing to note is that the Var-ND does not come with a lens cap, so be sure to order one in the appropriate size if you go this route. It does come with a nice leather carrying pouch.
So far I’m happy with my Vari-ND. It adds a interesting element to shooting outdoors, even when it’s just used lightly. It was pretty shady when I took the photo above, so I had the Vari-ND on a light setting. I’m pleased with how the colors look in that photo. There’s a richness to it that I like. I was using my Lumix GH2 and a Canon FD 50mm f/1.4.
Would you be just as happy using the Light Craft Workshop Fader ND or the Genus Fader ND? If you’re not an optics purist, it’s likely you will be. If you’re an optics purist who simply cannot afford the Heliopan or the Singh-Ray, I’m sure the Light Craft or the Genus will still suit you nicely. No matter what you decide to use, I feel confident saying that variable ND filters are worth checking out.