El Capitan in 40 Billion Pixels

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How one of the world’s largest photos is changing the way we climb Yosemite’s iconic big wall.

Gone are the days of hand-drawn topos, primitive sketches of a climbing route’s pitches and main features. Thanks to a two-year-long project completed this summer, we now have El Capitan—the Big Stone—captured in over 40 billion pixels.

Climbers and Yosemite guidebook authors Erik Sloan and Roger Putnam teamed up with photographers Eric Hanson and Greg Downing to create a 228,000-pixel wide image of El Capitan. A composite of 4,200 individual photos, the gigapixel panorama captured the wall in such high resolution one can zoom in to see every route, every feature in detail on the granite monolith.

A low-resolution version of the extremely high-resolution El Capitan Gigapixel Climbing Routes project. Click here to see the full image. (Photo courtesy of Eric Hanson, Blueplanet VR)

It was a feat of both photography and climbing—and a marvel of post-production computer processing. Where your typical high-end smart phone's camera can capture 12 megapixelsor 12 million pixelsa gigapixel is a billion pixels. And the image above has over 40 of them. Although the photo—and others like it—have become a boon to the climbing community in more ways than the creators ever imagined, it began as a form of artistic expression.

Hanson and Downing of Blueplanet VR and HyperAcuity (formerly xRez Studio) are pioneers of gigapixel photography. Their focus is to turn hi-res, 3D photography into virtual reality experiences, digitizing ancient monuments and art for all to view, almost like seeing it in person. It started around 12 years ago when they got their hands on a robotic camera mount that was once used to create time-lapses for IMAX-caliber films. “We reprogrammed it to carefully take overlapping images so we could capture the entire scene,” Downing says.

Attached to a tripod, the robotic mount systematically pivots a camera equipped with a super-telephoto lens to capture thousands of individual photos, typically row by row, each with a small overlap so later they can be digitally stitched together like puzzle pieces. The result is a single, remarkably high-resolution image. While composite panoramic photography is nothing new, Hanson and Downing took it to the gigapixel level by using thousands of shots instead of dozens.

“Robots make this a lot easier,” Downing says, “and can do it pretty quickly—45 minutes to an hour or more—so we can have consistent lighting.”

One of the first gigapixel images they created was of Yosemite’s Half Dome in homage to Ansel Adams, who shot many of his most famous  photographs in the valley. They thought of it as an art project, Downing says, but to their surprise, others in the valley found more and more uses for the image.

Greg Stock, a park geologist, studies rockfall in Yosemite. Despite its common occurrence (there have been more than 1,000 documented events in the past 150 years), rockfall is difficult to predict. Moreover, the rock scars left behind, and the chunks of fallen, pulverized stone, hide their causes well.

“[Stock] contacted us,” Downing explains, “and asked if we could do the same thing for the whole park, to create images where he could zoom in to see every crack in every rock.”

Having hi-res imagery as a baseline meant Stock could compare before-and-after photographs following each rockfall to learn more about the exact location, size and cause. “Geologists have asked these questions about rockfalls in Yosemite for the past 150 years, but now we’re doing it with a precision that earlier scientists couldn’t have dreamed of,” he told the National Park Service. That launched the Yosemite Extreme Panoramic Imaging Project in the summer of 2008 where 20 teams, led by Hanson and Downing, simultaneously photographed 10,000 images (for uniform lighting) to create 20 gigapixel panoramas of the national park. “Sometimes these photos are the only way of ascertaining the location and size of the fall,” Stock said. “We can immediately go to the photograph, zoom in on it and see what the mass of rock looked like before it failed. That can tell us a lot about why it failed.”

Climbers were quick to see the image’s utility.

“This changed the game,” says Sloan, about writing climbing guidebooks. Before this technology, guidebook authors had to rely on the often-faulty memory of other climbers to gather route descriptions. Fact-checking that data meant climbing each route themselves, which is impractical in a place like Yosemite that has more than a lifetime’s worth of rock. “But all of a sudden through Eric and Greg’s creation, climbers have essentially been able to canvass these huge cliffs.”

The images not only made the latest edition of the Yosemite guidebook more accurate and detailed, replacing hand-drawn route topos and low-res photos but also allowed climbers to easily scout for new climbs between the existing lines. “It’s such a gift to the climbing community,” Sloan says.

These images were of only the rock, but their recent El Capitan Gigapixel Climbing Routes project had a little something extra, which added another dimension of difficulty. Ninety-nine of El Cap’s 100 routes are drawn on the image, aid routes in red and free routes in yellow. The missing climb, the famous Nose that divides the wall, is instead shown on a human scale by integrating hundreds of images of Sloan (wearing a yellow shirt) and Putnam (wearing red) as they each ascend the 3,000-foot route, body length by body length, from the valley floor.

To capture the sequential shots in consistent lighting, the climbing team raced up the Nose in an impressive seven hours. And unlike their previous images, for the climbing phase of the El Cap panorama, Hanson and Downing had to forgo the robotic mount so they could manually track and photograph Sloan and Putnam as they climbed every move on the route.

Zoom in far enough, and you'll spot Erik Sloan (yellow) and Roger Putnam (red) as they climb every move on the Nose. (Photo courtesy of Eric Hanson, Blueplanet VR)

They had an early start and completed the first five or six pitches in the shade, so they returned the next day to re-climb and photograph them in the sun. In total, they took around 2,200 shots to capture the pairs ascent and another 2,000 photos to fill out the rest panorama.

Then came the editing process.

How do you seamlessly stitch together 4,200 photos? “Oh, it was a massive, massive process,” Downing laughs. “The software was not really made to do this type of image, and we had to come up with new workflows, so that was quite a challenge.”

Both photographers work full-time, so this passion project took two years of late nights to piece together. “An estimate for time is very difficult, but it’s definitely hundreds of hours,” he adds. It took Sloan a couple of months just to draw the routes and label the features. Finally, the gigapixel image was released to the world for anyone to view online, and it’s also available to purchase as a 40- by 60-inch print.

“In the end, it was an artistic expression,” says Downing, bringing it back to the project’s roots. “It’s difficult to take a unique image in Yosemite since so many amazing photographers have been there. We wanted to express something that hadn’t been expressed before, which was to show the scale of the rock and what it takes to climb El Cap.”

For the climbing community, the new El Cap image is both beautiful and useful. Instead of staring for hours at cryptic sketches on paper or even napkins, one can study a route in hi-res, from bottom to top, without ever leaving the ground.

“The sky is the limit,” Sloan says. “Hopefully this is the inspiration we need to ask ourselves, ‘What do we want to create? How can we come together to preserve and cherish these amazing resources? And what can we do to make the best tools for those who follow?’ It’s going to be exciting to see what inspires the next generation of climbers.”

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