He would need to get closer to Half Dome, he realized. So Adams and his friends set out to reach the Diving Board, a rock slab hanging some 3,500 feet above the valley floor. It wasn’t an easy hike in the first place, and Adams was loaded down with a 40-pound pack containing his camera, a handful of filters and lenses, and 12 glass plate negatives. This single-minded dedication would become typical of the photographer’s later process, in which he would spend weeks at a time in the mountains, scouting out the perfect location for a single photograph. (In fact, during two such trips, he missed the births of both his children.)
En route to the Diving Board, Adams made several exposures, and by the time the group reached Half Dome, he had just two plates left. They sat down for lunch, waiting for the sun to move high enough in the sky to illuminate the entire cliff face. By 2:30 p.m., Adams was ready. For his first shot, he used a yellow filter that he often placed over his lens to subtly darken the blue sky. But almost as soon as he’d released the shutter, he knew something was off.
“I began to realize, why, I’m not creating anything of what I feel, because I know the shadow on the cliff is going to be like the sky; it’s going to be gray,” Adams later explained
. “It will be an accurate picture of Half Dome, but it won’t have that emotional quality I feel.”
Instead, for the second exposure, he used a deep red filter that would darken the sky almost to black and emphasize the white snow on Half Dome’s cliff face. The filter made all the difference, as Adams quickly realized when he developed the photo later that night. He considered Monolith, the Face of Half Dome, Yosemite National Park, California (1927) his “first really fine photograph,” a career-changing image that marked his first successful “visualization”—Adams’s term for carefully determining all elements of a photograph before ever releasing the shutter. Over a decade later he would institutionalize this idea with his Zone System, a photographic technique that is still taught in schools today.