Capturing the grand sunrise/sunset vistas presented by the vast expanses of the western US landscapes can sometimes be especially challenging due to the lack of clouds. Without clouds or haze, the sky simply fades from a very pale, burnished blue to gray. No drama. No flash of color. No spectacular light show. Nothing to add drama and interest to a photograph. Of course, you can always shoot landscapes that show little or no sky, but grand scenic landscapes usually look best with an interesting sky. Fortunately, Mother Nature has been kind enough to put on a little show that can help enrich boring blue skies. Not surprisingly, it is the same thing that we photographers work with all the time—light and shadow—only it’s in an otherwise empty sky.

Tranquility reigns as the snow-clad peaks subtly reflect the soft pastels of the earth's shadow. (Camera: Nikon N90s; Nikkor AF 80-200 f2.8 D; Velvia, ISO 50)

The dry air in the arid west, particularly at higher altitudes, allows us to see a phenomenon that frequently occurs when the sun is just below the horizon—a band of pink, transitioning quickly into blue, appears above the opposite horizon. Sometimes intense, sometimes very faint and subtle, this line is the shadow of the earth cast across the atmosphere. The shadow of the planet is projected through the atmosphere the same as shadows of backlit trees are projected through fog. Only this is a much more extreme phenomenon. The lower, shadowed portion of the sky is usually a dark blue to a blue gray that transitions very quickly into a pink band that fades into the washed out pinkish blue sunlit sky above.

A large expanse of blue sky, while making for pleasant conditions for the photographer, can turn into a monotonous negative space in a photograph. Taking advantage of the earth’s shadow adds an unusual artistic element to your composition, breaking up the large negative space created by an empty sky. And if you’re fortunate enough to be near water, the subtle hues of the earth’s shadow reflected in the water are not to be missed.

The Rio Grande River in southern Colorado’s San Luis Valley reflects the soft pink sky from a fairly sharp earth’s shadow. (Mamaiya RZ67 II; Mamiya 65 mm; 15 seconds at f/32; Velvia, ISO 50)

Photographing the earth’s shadow is surprisingly simple. I believe that the earth’s shadow appears more prominently at sunrise. I attribute this to less dust and fewer clouds in the morning air, but it may just be my preference for shooting at sunrise. So most of my images are made before sunrise. In order to photograph the earth’s shadow, you need to solidly support your camera to accommodate long exposures. You can expect exposure times of ¼ second or more, even with the widest aperture.

Metering Options
I set my camera to properly expose the foreground and let the sky take care of itself. I meter the scene in one of two ways. One is to set my camera to meter in matrix mode and meter the scene with just enough sky to show the earth’s shadow. Compensating for the overall tonal values of the scene as you normally would (decreasing the exposure for predominantly dark subjects and increasing it for predominantly light objects), this usually gives a good exposure for the foreground and a reasonable exposure for the sky. I bracket ±½ stop and pick the shot that shows the earth’s shadow and foreground to best advantage. The other way I determine the exposure is to use a gray card. This also gives a good overall exposure, but again, I bracket ±½ stop. That’s it. No magic filters. No fancy techniques.

Reciprocity Failure
If you’re like many landscape photographers that shoot at the smallest aperture to achieve maximum depth of field to keep everything in focus, then very long exposures will be required. A sturdy tripod and sound photographic technique are crucial. Your camera must very stable and, if possible, operated in the mirror up mode to avoid camera shake when you trip the shutter. By long exposure, I mean from 1 second up to 60 seconds. The actual time will vary depending on your lens, aperture and film speed.

	The blue/pink line of the earth’s shadow adds some interest to a clear sky in this striking display of autumn color in Grand Teton National Park. (Mamaiya RZ67 II; Mamiya-Sekor 250 mm; 8 seconds at f/16; Velvia, ISO 50)

	A stark, clear sky over the Grand Canyon is enhanced by the color transition of the earth's shadow. (Mamaiya RZ67 II; Mamiya 65 mm; 10 seconds at f/32; Velvia, ISO 50)

Naturally, when making long exposures on film, the question of reciprocity failure comes up. Simply stated, reciprocity failure is when film does not respond to low light conditions as it does under normal light. Think of making an exposure like filling a water glass. You can fill the glass very fast (a wide aperture and fast shutter speed) or very slow (a small aperture and long shutter speed.) Either way, it takes the same amount of water (light) to fill the glass. If you fill the glass extremely slowly, when the water faucet is just trickling into the glass, some of the water evaporates before the glass fills. Therefore, it actually takes more water dripping from the faucet to fill the glass than when the glass is filled “normally.” During very long exposures, usually 1 second or longer, you need to compensate for the “evaporating water” by increasing the exposure time. There is also a very slight color shift in color films in low light conditions. This is because the different color layers in the film do not respond to light in exactly the same way. Normally the differences are too slight to be seen, but long exposures magnify those tiny differences.

Since different films react differently under low light conditions, it is necessary to check the manufacturer’s technical data for the proper correction factor for the film you’re using. For my preferred film, Fuji Velvia (RVP 50), Fuji recommends adding 1/3 to 1 stop to the exposure and using a 5M to 12.5M color correction filter (Fuji Data Sheet AF3-960E) for exposures of 1 second or longer. Shooting the earth’s shadow, I find that I do not like the results that I get using these corrections. Exposing to get a “normal” looking exposure tends to look a bit unnatural, making the foreground too bright for the sun being below the horizon. It also washes out the sky, losing the earth’s shadow. By underexposing ½ stop, the foreground is a little dark, adding a sense of time, emphasizing that the sun is below the horizon while preserving the earth’s shadow above the horizon. The slight color shift is usually not noticeable in a natural scene under these lighting conditions. I recommend that you experiment a little to determine what results you prefer. If you prefer a more normally exposed foreground, a graduated neutral density filter may be necessary to preserve the earth’s shadow in the sky. Most of the time, I don’t use any filter. All of the photos accompanying this article were taken without any filter or enhancement.

The subtle shades of the earth’s shadow are reflected in a quiet pond near the top of Beartooth Pass on the Wyoming-Montana border. (Mamaiya RZ67 II; Mamiya 65 mm / Mamiya 1.4x tele; 30 seconds at f/22; Velvia, ISO 50)

For the digital photographers, capturing the earth’s shadow may still be beyond the capability of the technology. So far, I have not yet seen a satisfactory earth's shadow photograph taken with a digital camera. Although, digital cameras are not plagued by the problem of reciprocity failure like film cameras, digital cameras have their own technical issues—in this case, noise. During long exposures, the noise generated on a digital image can leave the image virtually unusable. For now, the only hope for a digital image is to use a large aperture and sacrifice the depth of field for a shorter exposure time.

The next time you’re faced with a clear, blue-sky sunrise/set, don’t despair. Simply turn your back on the sun and look for the earth’s shadow just above the opposite horizon. The subtle colors of the earth’s shadow can turn a boring blue sky into an interesting band of pink and blue.