Exposure danger zones come in two basic categories: situations where the scene is not mid tone, and situations where your sensor can’t record the wide range of brightness levels in the scene. In the examples that follow, Glenn Randall, landscape photographer and author of The Art, Craft, and Science of Great Landscape Photography, explains how to hold detail everywhere in the frame.
Note: all photos in this post are by Glenn Randall.
Exposure Danger Zones
Mostly White | Any scene that is mostly white: snow, waterfalls, white sand. You should increase exposure to compensate.
Hallett Peak from Dream Lake after a
44-inch snowfall, Rocky Mountain National Park, Colorado
Predominately Dark | Any scene that is predominately dark: very dark rock, dark-furred animals.You should decrease exposure to compensate
Bison near Lookout Mountain, Colorado
Shaded Foreground, Sunny Background | Any scene where you have an important foreground in shade and a background in full sun. If the foreground is shaded only by thin clouds, the range of light intensities may still be within the range of your sensor if the scene is perfectly exposed. If the foreground is shaded by thick clouds or something solid, such as a mountain or canyon wall, the range may be beyond the ability of your sensor to hold good detail everywhere in a single capture.
Lupines in Silver Creek Basin and Treasure and Treasury Mountains, Maroon Bells-Snowmass Wilderness, Colorado
Backlit Scenes | Any backlit scene, meaning a scene where you are looking toward the sun or other light source (even if it is out of the frame). The sun in a clear sky is way too bright to expose with any detail, but even the sky around the sun is likely to be too bright to hold detail, and you may have difficulty achieving proper exposure in both the sky and the foreground shadows.
January sunset at Delicate Arch, Arches National Park, Utah
Snow & No Snow | Any scene in which only half the landscape is covered in snow, even if the entire scene is in full sun. A classic example is a green, flower-filled meadow with snowcapped peaks in the background.
Ski mountaineers approaching Mt. Sanford, Wrangell-St. Elias National Park, Alaska. Notice how the shadowed faces have gone completely black.
Cloudy Days | Any scene shot on a cloudy day when you have sky in the frame. The lighting on the land is very even, which means your sensor can easily record detail everywhere in that part of the image. However, the sky is always wickedly bright and can easily blow out to a very distracting pure white.
Columbines in American Basin, Handies Peak Wilderness Study Area, Colorado
Subjects and Reflections | Any scene with a pond or lake where you need a wide-angle lens to include both the subject and its reflection. The amount of light reflected from water is dramatically dependent on the angle of incidence of the light. The angle of incidence is the angle between the path of the incoming light and a line perpendicular to the surface of the water. Yes, I know that’s counterintuitive, but that’s the way scientists define it. Light with an angle of incidence of zero plunges straight down into the water; light with an angle of incidence of 90 degrees is traveling parallel to the water’s surface. Light that strikes the water at a high angle of incidence (meaning it just barely grazes the surface) is nearly all reflected. The difference in exposure between the subject and its reflection might be only 1/2 stop— easily within the range of your sensor to capture good detail everywhere. If a 50mm or longer lens (on a full-frame sensor) is wide enough to include both the subject and its reflection, you’re probably safe. If the angle of incidence is low (meaning the light is plunging steeply down into the water), much of the light is transmitted into the water and the difference in exposure between the subject and its reflection can be four or even five stops. That’s too big a difference for your sensor to straddle comfortably. If you need a 24mm or wider lens to encompass both the subject and its reflection, you’re in an exposure danger zone.
reflected in Lake Helene, Rocky Mountain National Park, Colorado, shot on 4×5 film with the equivalent of a 20mm lens
Night Scenes | Any night scene, particularly if your foreground includes evergreen trees and the sky includes the glow of a nearby city.
The Milky Way over
Longs Peak from Trail Ridge Road, Rocky Mountain National Park, Colorado
Closing Thoughts | Once you’ve recognized an exposure danger zone, how do you deal with it? You can, of course, just “spray and pray”—shoot a whole bunch of frames of the scene at different exposures and hope for the best. However, that’s hardly an ideal solution. First, things may be happening so fast that you can’t bracket exposures. What if you’re shooting sports, or wildlife, or your daughter’s first step? What if you’re shooting flowers in a grand landscape and the wind only stops once during the fleeting seconds of perfect light? In some situations, your first capture is your only capture, and the exposure had better be right. A mindless strategy of always bracketing your exposures can also fail when the dynamic range of the scene exceeds the dynamic range of your sensor. In that situation, no single capture will contain all the detail you want in both the highlights and shadows. While bracketing is sometimes essential, it should not be the only tool in your exposure-strategy toolbox.