Aerial Panoramas: Stitching Together Moments Captured in the Sky

Like many photographers who learned their craft shooting film, I will never forget the moment in a high school darkroom when I made my first black and white print. It was like magic watching as the image emerged on the prints in the developer tray, and it was the beginning of my love affair with the medium.

On a recent National Geographic magazine assignment to photograph the effects of the drought in the American West this past spring, I had some similar moments of discovery. This time I wasn’t standing in a darkened room full of smelly chemicals lit by a red safelight, I was sitting in a hotel room with my laptop, digitally stitching together vertical aerial images to make panoramic photographs. The joy and satisfaction of seeing the finished image appear, however, reminded me of how I felt making those first prints back in the day.

The assignment to photograph the ongoing drought was an important one, and I needed to make dramatic photographs of places that had been depicted many times before. I came up with the idea to do aerial panoramic photographs to illustrate the sites where the reservoirs were at half capacity, where there was a light snow pack in the mountains, and of the desert cities dependent on an ever-dwindling amount of water.

The first stop was to Shasta Dam. The reservoir behind the dam collects snow and rain runoff from a huge watershed in Northern California. This water is essential for farmers in the Central Valley and the southern cities. I scouted the best location on Google Earth, which has become a great resource for photographers doing research, and determined that the scene would get the best light at sunset. I could even tell from Google Earth that the best eye altitude was about 2,700 feet. As the pilot hovered a piston-engine Robinson R44 helicopter at the selected location in clear skies and low winds, I shot the photos from the left back seat with the door removed. I made nine vertical photos, each with a 50% overlap with a 24mm lens mounted on a gyro stabilizer.

After we landed I went back to the hotel, made the TIF files of all nine images, and used PhotoMerge in Photoshop to make the panorama. It took several seconds for my computer to crunch all the data, but after those moments of anticipation the panoramic image flashed on the screen. Just like in the developer tray, the result is either a joy to behold or a time to come face-to-face with your mistake. In this case, the images all stitched together seamlessly and the nice light on Mt. Shasta was the exclamation point. The panorama took in about a 160-degree view with little distortion, a viewpoint not possible with a single capture. This type of digital photography opens up a whole new way of viewing the world. It’s a great time to be a photographer!

Next, I drove south to the Owens Valley in Eastern California and found a helicopter operator at the Mammoth Lakes Airport. An important photograph for the story was to show the light snowpack this year in the Sierra Nevada mountain range. I used a similar approach to make the panorama, except this time I needed to hover at around 12,000 feet. This requires a more powerful helicopter. Fortunately, an experienced local pilot, Ed Rosky, had just purchased the perfect machine for the job, a Robinson R66 turbine helicopter. I made 17 exposures to take in a view of 240 degrees, so I had to direct Ed to rotate the helicopter while remaining at the same position and altitude. This is not a task for a beginning pilot.

A final stop was in Phoenix to photograph the sprawling Valley of the Sun in the midst of a severe drought. This metropolis in the desert is only possible because of water diverted from the Colorado River. On Google Earth I scouted some housing developments in Sun City that had a circular pattern from the air. I photographed at dawn looking east into the rising sun from a small but robust Enstrom helicopter. The exposures were 1/15th second at f1.4, right on the edge of what is possible with the optical and vibration limitations of aerial photography. When this panoramic appeared on my laptop screen it was perhaps the greatest moment of the assignment. The photograph actually looked better to me than the actual scene, a reminder to me of the process of magic and illusion that is sometimes called photography.

See more images from the October 2014 feature story, “When the Snows Fail.”
See more of Peter Essick’s work on his website.

Related Story: A Day to Remember in the Ansel Adams Wilderness
Related Story: Peter Essick’s Journey into Environmental Journalism