The sky was clear on the August morning when I woke before sunrise at Thousand Island Lake in the High Sierra Mountains near Yosemite National Park. I was photographing a story for National Geographic magazine in an area known as the Ansel Adams Wilderness, which is named for the famous landscape photographer whose art celebrated the beauty of the region. A cloudless day like this would likely have been met with a lack of enthusiasm by Adams, who once referred to these as “bald-headed days”—when the bright sun would reflect off his bald head and there would be many hours of unappealing light for photography. There are, however, a few minutes of nice light at sunrise in the