Versatile Graduated Neutral Density Filters

I've been using graduated neutral density filters (what I'll refer to hereafter as Grad-NDs) since the early 2000s. At the time, I was shooting slide film and the exposure latitude of the film was about five stops of light from pure white to pure black. To enable me to capture details and colors in scenes that had greater than five stops of light, I used Grad-ND filters to essentially darken the brightest areas anywhere from 1 to 5 stops bringing the entire scene into or at least closer to that 5 stops of exposure latitude. Digital sensor technology has improved to the point I believe a modern sensor has closer to seven stops of exposure latitude and thus captures more shadow and highlight detail than the slide film I used to use. Even so, since I don't like to use high-dynamic range (HDR) capabilities in camera or on the computer due to my belief that the result is more digital art than photograph, I continue to use Grad-NDs in my digital photography.  The same holds true for the creation of composite images from multiple source photos; it's not something I consider to be a photograph anymore and is instead digital art created from multiple photographs.

If you don't know what a Grad-ND looks like, it is simply a filter with part clear and the rest gray (typically a neutral gray although cheaper ones also have a slight coloration to them which impacts the image). The dividing line is nearly always right in the middle of the filter but not always. Grad-NDs can have a wide or narrow area where the transition from clear to gray occurs. There are even reverse Grad-NDs, which have the darkest area right next to the clear area, then gradually get lighter toward the edge. I have been using Tiffen Grad-NDs for years because they are neutral gray (no color cast) and made of glass which is more resistant to scratches than other brands' resin/plastic Grad-NDs. Some manufacturers offer screw-in Grad-NDs but I recommend against them because you are forced to place the gradient over exactly half of your image, and you will rarely find a composition where that is right where you want it. Instead, I recommend rectangular Grad-NDs because they allow you to rotate and slide them up and down to place the darker portion wherever you want. On SLRs you'll need to use the depth-of-field preview, look through the viewfinder, then slide the Grad-ND around on the front of the lens until you see the darker area exactly where you want it, which likely is over the brightest area of the frame.

I have carried only two Grad-NDs with me for years and they are the Tiffen ND0.6 and Tiffen ND0.9. What those numbers mean is that the ND0.6 holds back two stops of light on the gray half, and the ND0.9 holds back three. I haven't seen any need for a single stop Grad-ND, although I often use both the 2-stop and 3-stop filters for a single image, giving me 5 total stops of control in some areas.

What makes Grad-NDs so versatile, and inspired me to write this article, is that they aren't just for skies. Many people use them to darken bright skies enough to keep light blue from becoming a washed out, unattractive white in the resultant photo. I used mine for that exact purpose in the accompanying photo of the Mormon Row barns in Grand Teton National Park, WY at sunrise. The sky over the mountains and the peaks bathed in sunrise light were more stops of exposure than the foreground that was still in shadow. I used a Grad-ND in the traditional way, to darken the sky and mountains and bring their exposure closer to the foreground, allowing me to expose the entire scene in a pleasing manner. If I hadn't used a Grad-ND, either the foreground would have been dark or the snowcaps and sky would have been washed out.  One detractor of this photo is the edge of something in the top right. I should have caught and fixed that while shooting.

Another nearly typical use for a Grad-ND can be seen in the photo of Glade Creek Grist Mill in Babcock State Park, WV. I arrived early in the morning and found the sky and portion of the forest illuminated by the morning sun to be too many stops above the creek in the foreground, so used a Grad-ND over both to even out the scene's exposure allowing me to produce what you see. Since there was sky behind the trees in shade in the foreground, I covered them with the Grad-ND as well and you can tell because they are darker than I'd prefer. That is one disadvantage of a Grad-ND. You have a straight line where it starts to get dark, so have to place that as best as possible across scenes that rarely have a straight delineation between the bright and dark parts.

Now we will get into some of what I'd call atypical use of the Grad-ND. The accompanying photograph of White's Mill in Abingdon, VA, was also created at sunrise. I found the sky, mill, and trees in both the top left and distant right illuminated by the morning sun to be brighter than the fence and grass in the foreground. Thus, I used a Grad-ND diagonally following the top of the fence to darken the mill and trees to get their exposure more in line with the fence and grass. I find the result more pleasing and balanced than had I let the grass go dark or the sky and trees go light.

One more atypical use of a Grad-ND was on the Arlington Covered Bridge in Arlington, VT. I found the sky, bridge, and yellow foliage alongside the stream were too bright to get a good exposure for the reflection of the bridge in the water, so used both my Grad-NDs to even out the entire scene. When using both I will sometimes put the line between clear and gray for both in the same place, but just as often place those lines in different places and even use each filter at a different angle in order to get the best overall exposure across an image.

Who says the gray part of a Grad-ND needs to be at the top? For the photograph next to this paragraph of a paint pot on Paintpot Hill, Yellowstone National Park, WY, I actually flipped my Grad-ND and had the gray part on the bottom! The off-white clay-like earth on the bottom of the image was very light, while the evergreen trees in the background were darker. Using a Grad-ND over that clay allowed me to get a brighter and more pleasing exposure for those trees in the background.

As you just saw, you can use Grad-NDs with the gray part at the top, as is usually done, but can also use them upside down when you have the brightest areas at the bottom of your composition. Can you also use them over only one side of a composition? Of course! For the accompanying photograph of a church in Plymouth Notch, VT, I could not get detail in the shadow side of the church on the left while also getting detail in the autumn colors in sun in the middle and right, so used my Grad-ND to darken the middle and right side of the image allowing me to capture detail in the building on the left.

As you can see, Grad-NDs can be used for all sorts of challenging exposure situations, and I always have mine with me unless I'm out exclusively to photograph macro subjects or with my large lens exclusively to photograph wildlife.

October 2020 Addition

I just got back from a week in West Virginia and have two more scenes with photos showing each with and without the Grad ND filter for comparison.  The first is Claypool Falls with a Grad ND over the left portion of the image.  The second is Campbell Falls with a Grad ND over the bottom portion of the image.

Claypool Falls

  • Claypool Falls, WV with Grad ND filter over left side of photo giving a more pleasing, balanced exposure of the falls, forest, and area behind the falls which was in shade. © 2020 Kenneth R. Sheide

  • Claypool Falls, WV with no Grad ND filter used. Note how dark the area is behind the falls. © 2020 Kenneth R. Sheide

Campbell Falls

  • Campbell Falls, WV with Grad ND filter over bottom leaves and rocks giving a more balanced and pleasing overall exposure. © 2020 Kenneth R. Sheide

  • Campbell Falls, WV with no Grad ND filter in use. Note how bright the rocks are in the foreground compared to the falls and forest in the background. © 2020 Kenneth R. Sheide

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