|A graduated neutral-density filter balanced the sky exposure with the foreground lupines, but was positioned too low in the scene, making its use obvious.|
Since so many scenes in nature contain a greater range of light than our cameras (film or digital) can record, graduated neutral-density (ND) filters are a staple in the landscape photographer’s bag.
Grad ND filters are generally used to darken a background that’s significantly lighter than the foreground. Common examples are sunrises and sunsets with bright skies and foregrounds in shade or mountain scenes where a snow-covered mountain is much brighter than the foreground.
But there are no rules saying you have to use the filter to tone down a background. Occasionally, a foreground is brighter than a background, especially scenes with a sunlit snowy foreground and a background of dark evergreen trees.
Following are 12 tips to help you get the most out of your graduated ND filters.
|It’s easy to overdo the polarizer effect (bottom). The sky in the partially polarized shot at left looks more natural (top).|
1 Use the depth-of-field preview to position a graduated ND filter.
Grad ND filters are great for controlling contrast in landscapes. The trick is in using them so that no one can tell you’ve done this. The first step is in choosing the right filter (one-stop, two-stop, three-stop; hard- or soft-edged). The secon and possibly more important step is in correctly placing the filter. If the filter is placed too high, the transition will be seen in the sky, too low, and the foreground will have an unnatural "shadow" across it.
The best way to accurately place a graduated filter is to press your depth-of-field preview button while looking through the viewfinder, which makes it easier to see the transition. Moving the filter up and down also helps.
Singh-Ray Split Grad ND Filters
B+W Grad ND Filter
2 Handholding graduated ND filters for speed and accuracy. Along the same lines, I find it easier and more accurate to handhold graduated ND filters. For one thing, it’s easier to move and place the filters handheld rather than struggling with a filter holder. Secondly, when the light is changing fast, I often need to switch filters quickly, and using a filter holder just slows me down.
Granted, this takes some practice, as you need to make sure that the filter completely covers and is also flat against the lens. The larger 4x6-inch grad filters available from Lee, Singh-Ray and others can make handholding these filters easier.
I use one hand to press the depth-of-field preview button and another hand to hold the filter. How, then, do I trip the shutter? I put the cable release in my mouth and use my tongue. No, seriously.
Another advantage of handholding a grad ND filter is that you can move it during the exposure. Sometimes you may need to further "feather" the transition. By moving the filter slightly up and down during the exposure, you’ll have even more control over how the transition area interacts with the scene. This is especially useful when you need a soft-edged filter, but all you have is a hard-edged filter.
3 Use a polarizer to cut glare from foliage. Polarizers are handy filters to have. They’re certainly the most versatile filters. The main use I find for them is to cut the glare from foliage, allowing all the colors to come through. I usually use polarizers in the forest on overcast or rainy days to take the sheen off leaves, needles and rocks. This is what makes those forest shots you see so green. Polarizers are essential filters for forest, stream and waterfall photography.
You’ll lose a few stops of light, requiring longer shutter speeds, but that shouldn’t be a problem if you’re shooting from a sturdy tripod.
|The sky over this field of California poppies is a little light in a straight shot (above); adding a polarizing filter makes the sky look better (below).|
4 Use a polarizer to‚ "see" through water. Interesting things can lie just beneath the surface of lakes and streams. Polarizers can cut the glare from the surface of water and allow us to see colorful rocks and interesting patterns. These make great foregrounds for landscapes, as well as interesting subjects on their own.
5 Save the streams. While polarizers are effective in removing glare from water surfaces, sometimes they’re too effective, essentially making streams disappear. If you have a stream in your photo, the viewer needs to know it’s there. I like to turn the polarizer to its maximum effect and then back it off just a bit, restoring a little glare on the surface of the stream. Otherwise, the stream can look more like a trail or a road rather than a stream.
6 Use a polarizer instead of a graduated ND filter to darken the sky. If you have a blue sky that’s just a bit too light, say about a stop too light, which often happens near the horizon, you can probably darken it with a polarizer rather than using a one-stop graduated ND filter. This way, you get the sky the way you want it, along with the added benefit of cutting glare from foliage.
|Rain on the polarizing filter turns this into an ethereal imag|
The polarizer will have a greater effect if your camera is pointed 90 degrees to the sun, in other words, when the sun is either to your left or right. Be careful when using a wide-angle lens, though. Because a wide-angle lens takes in a large angle of view across the sky, it’s very easy to have one part of the sky appear darker than the rest.
7 Use a polarizer to dial in the sky. As we’ve just seen, it’s possible to darken skies using a polarizer. But sometimes it’s easy to go overboard, and the result can be a nearly black sky. This most often happens at higher altitudes.
Many people turn the polarizer to its maximum effect because that’s what looks best in the viewfinder—that’s what gives us that "oooh" effect. But remember, film and digital sensors don’t see things quite the same way we do. Compared to our eyes, film and sensors are capable of recording only a very narrow range of brightness values. Therefore, that deep blue sky you see in the viewfinder may look nearly black to your film or digital camera. The way to know how the sky will be rendered ahead of time is to use your in-camera spot meter in the manual exposure mode.
Here’s how: Look through the view-finder and rotate the polarizer until you like what you see. Determine an exposure in the manual exposure mode by spot-metering something in the scene (not the sky) that has a medium tonality (the same reflectance as a gray card). Change your aperture and shutter as you normally would to set an exposure and zero-out the meter.
Now, point your spot meter to the sky and watch the analog meter in your viewfinder. Normally, skies look best if they’re a little lighter than a gray card. If your meter reads darker than medium (on the minus side of the scale), the sky will look unnaturally dark. If it reads -2, the sky will be nearly black. This can be dramatic, but is it what you want? If not, turn the polarizer until the sky is a little lighter and repeat the above metering exercise. Do this until the meter indicates that the sky is the tonality you wish it to be. You may find that you didn’t need the polarizer in the first place.
For example, in the first picture of the red rocks, they’re of a medium tonality. The light-colored sandstone in the foreground is about one stop lighter than medium. But the sky is about two stops darker than medium. This is what can happen from overpolarizing. By using the spot meter, I can tell ahead of time if this will happen and take steps to correct it, as shown in the second picture.
8 Do I need a polarizer? If you’re not sure you need to use a polarizer, instead of taking the time to attach it to your lens, simply hold one to your eye and rotate it. If you see something you like, go ahead and attach the filter to your lens. Some polarizing effects are subtle, like when you want to reduce glare from leaves. In this case, keep your eye on a small section of the scene rather than the whole. Be sure the filter threads are facing you, just as they would be on the lens.
In a straight shot, the sky is too light (above); a -1 stop graduated neutral-density filter fixed that (below).
9 Using neutral-density and polarizing filters to slow shutter speed.
There are interesting and creative things you can do with long shutter speeds. You can stretch out clouds, record flowers blowing in the wind, create misty shorelines, and blur waterfalls and streams to extreme levels. Use neutral-density and polarizing filters to achieve these effects.
Polarizers cut about two stops of light, and neutral-density filters are available in a variety of densities from one to four stops (filters up to 20 stops are also available).
On brighter days, I’ve often used a polarizer with a two-stop ND filter to slow the shutter speed sufficiently to blur water. Lately, I’ve been using Singh-Ray’s Vari-ND filter, which allows me to dial in up to eight stops of neutral density. This is a great creative tool.
10 Fog or mist a filter or lens for ethereal effects.
To add a touch of mystery to a landscape, try fogging or misting any filter or even the lens itself. After fogging the lens, look through the viewfinder and trip the shutter when the scene looks appropriately foggy. Fogging the lens or filter with your breath is easy to do, but depending on conditions, may not last long; you might need to work quickly. Keep in mind that foggy scenes generally look better overexposed by about one stop.
11 Natural filters.
Sometimes you don’t need to look any farther than the end of your lens for an entire array of filter choices. By shooting through flowers, grasses—just about any foliage—you open the door to a whole store of natural filters. Just use a wide aperture (ƒ/2.8, ƒ/4, ƒ/5.6), and get close enough so that the foliage is out of focus and produces a soft filtering effect. To get the exact effect you’re after, be sure to use your depth-of-field preview button to fine-tune your aperture setting.
12 Warming filters. Most digital shooters don’t use warming filters anymore. Film shooters need them to counteract the blue light from photographing in the shade on a sunny day. One reason all photographers should keep a warming filter in their bag is for fill-flash. When you use fill-flash at sunrise or sunset, the cool, noontime light emitted by the flash is a stark contrast to the warm light from the sun. You can use a warming filter, like an 81B or 81C, to cover the flash and match the color from the flash to the ambient light. When covering your flash, try using varying amounts of filtration. In other words, don’t just cover the entire flash head with the filter; try covering only a quarter or half of the flash head. This way, you control the strength of the warming effect in the foreground. Digital shooters can see right away how they’ve done. Film shooters will want to "bracket" filter coverage until they get a feel for its effects. Filter gels are also great for this. I use a "sunset"—colored gel cut to various widths to balance fill-flash light with the sunset or sunrise light. [Editor’s Note: Heat from the flash can damage gel filters.]
So there you have it—a few ways to get the most out of your filters and expand your photographic horizons.
Rod Barbee is the author of The Photographer’s Guide to Puget Sound and Northwest Washington (Countryman Press, 2007). To learn more about his workshops and books, visit his website at www.rodbarbee.com.