From a Christie’s online article:
Adams’ ‘visualisation’ strategy marked a shift away from Pictorialism, a much more manipulated photographic style, which had influenced his early work. His desire for sharper focus and deeper tone and contrast (he called it ‘an austere and blazing poetry of the real’) led to him becoming a leading figure in pure — or straight — photography.
Arguably no other photographer of his era knew more about photography than Adams. He wrote ten technical manuals on the discipline, and even advised major figures like Strand and Edward Weston, his friend and fellow West Coast photographer.
He also consulted for Polaroid and Hasselblad. Without such technical mastery he would not have been able to react with such immediacy to the quickly changing conditions of landscape.
One of his most famous works, Moonrise, Hernandez, New Mexico, 1941, needed snap judgements of immense sophistication to capture the momentary effect of sunset light on the foreground, and establish a balanced tone and focus with the distant peaks, evanescent clouds and darkening sky.
Boomers Daily 