Adams developed the Zone System as a way to determine proper exposure and adjust the contrast of the final print. The resulting clarity and depth characterized his photographs and the work of those to whom he taught the system. Adams primarily used large-format cameras despite their large size, weight, setup time, and the film cost, but because their high resolution helped ensure sharpness in his images.
Unknown to many, Adams did not work exclusively in black and white he experimented with colour, as well. A few examples of his colour work are available in the online archive of the Centre for Creative Photography at the University of Arizona. His subjects that he shot in colour ranged from portraits to landscape to architecture, a similar scope to that of his black and white work. There are two main reasons, according to an expert source, why Adams preferred black and white.
The first was that he felt colour could be distracting
The second reason was that Adams was a “master of control”. He wrote books about technique, developed the “Zone System”—something which helped determine the optimal exposure and development time for a given photograph—and introduced the idea of “pre-visualization”, which involved the photographer imagining what he wanted his final print to look like before he even took the shot. These concepts and methods allowed for nearly total control of all the potential variables that factor into a final print. Because of his love for control, Adams disliked colour since it lacked this element that he had mastered with black and white. However, toward the end of his life, the expert source said, Adams admitted that he wished he had been able to better master the technique of controlling and manipulating colour..
He exclusively uses Film