The accessibility of works by the master photographers seems to run afoul of the copyright police. Relatively few Adams, Eastman, Weston, etc images are easily accessible (with my usual art resources) on the web, and often in poor quality images, with offers to sell you a poster. Few individual museums have more than one or two images each, and there seem to be only a handful of sites specializing in collections by photographers.
Ansel Adams made his first photographs during a 1916 vacation trip to 1902 San Francisco Yosemite National Park in California. Even then he exhibited the first 1984 Carmei, manifestations of what was to become characteristic of his entire work: a combination of superb photographic skill and a deep admiration for the American landscape. Adams originally wanted to become a pianist. It was only after an encounter with Paul Strand in 1930 that he discovered that photography was his true medium of expression. Strand's concept of pure photography made a lasting impression on Adams and motivated him to clarify his own intentions.
In 1932 he joined photographers Imogen Cunningham, John Paul Edwards, Sonya Noskoviak, Henry Swift, Willard van Dyke and Edward Weston to found the group "f/64". Members of this group dogmatically practiced a style of photography that emphasized the greatest possible depth of field and the sharpest reproduction of details. Fascinated by the precise rendition capabilities of their medium, the photographers particularly favored close-ups of individual subjects.
Adams' photograph Rose on Driftwood is an example of this It was in 1941 that Adams created his famous "Zone System", an aid for determining correct exposure and development times for achieving an optimal gradation of gray values. Adams disseminated his photographic ideas and procedures through numerous books and seminars.
In 1946 he founded the Department of Photography at the California School of Fine Art in San Francisco. In 1962 he retired to Carmel Highlands. Adams spent a considerable part of his life as a landscape photographer in America's National Parks, about which he published more than 24 photographic books. During that time, he not only practiced his photography, but he also used his work to generate public interest in the parks, which he supported
[numerous "typos" edited in the last paragraph above.]
Only 5 images showing examples of Adams' work at the BLOWUP site.
The articles at the bottom of the ArtCyclopedia page (first link above) may be of interest. I subscribe to Smithsonian, so I've read the one there and it's a good one; but others may be good as well.
Ansel worked from the beginning of his photo career at attempting to capture the most detailed and "real" representation of natural scenes. His mastery came largely from his skill at selecting scenes especially worth preserving, and then in carefully using the best methods available within the technology of film. While he could have used Photoshop methods to do some dodge and burn, and could have made brightness and contrast adjustments, I doubt he would have been interested in most of the other tools available there. He chose film technology, and worked it to the limits of the equipment and methods available within that technology. He documented, and made available, the techniques he developed, and his interest was in advancing photo methods and materials. His works don't need, and would not have benefited from, any additional gimmickery.
Photoshop was available(?) during his last years, albeit rather crude compared to now. There's no evidence that I've seen that he was interested in it. I do suspect that most of those numerous poster offers rely on big scanners and a little "shopping" but I doubt that the resulting posters improve on the original prints that Ansel made.