How did aerial photography change Edward Steichen’s approach to photography?

Edward Steichen’s experience as the head of aerial photography for the American Army in France during World War I fundamentally shifted his artistic philosophy. The rigorous technical demands of this military role caused him to abandon the "vaporous symbolism" of his earlier Pictorialism style.1

Following the war, Steichen moved away from the soft-focus, painterly aesthetic he had previously championed. Instead, he embraced optical clarity and a greater objectivity of description in his work. This transition led him to spend several years experimenting with the realistic effects of light, tone, and shadow, famously photographing a simple white cup and saucer over a thousand times to master the subtle gradations of black, white, and gray.1