Edward Weston looked to nature as a source of poetry and metaphor. His photograph of an oak tree with limbs stretching out into the darkness presents the tree as a dynamic sign. Weston once stated that the goal of his art was to reveal "The Thing Itself . . . to photograph a rock, have it look like a rock, but be more than a rock." This idea of looking at the symbolic meaning of form while taking "straight," sharply focused images was foundational for photographers favoring a more subjective approach in the 20th century, particularly in the United States.