For those of you "pure" photographers who wouldn't touch Photoshop with a ten foot pole, here is a great master with differing views.
“The negative is comparable to the composer’s score and the print to its performance. Each performance differs in subtle ways.” – Ansel Adams
A person can appreciate Adams's contributions to photography without wanting to emulate him or even like his work. For me, taking a picture is all about capturing what I see with as much fidelity to the real subject as I can manage.
In the quote from Adams below, I would prefer Jackson's approach to that of either Adams or Weston; I prefer photos that are realistic, not imprints of the artist's visualization.
"Both William Henry Jackson and Edward Weston photographed the American West extensively. But in my opinion, only Weston’s photographs qualify as art. Jackson, for all his devotion to the subject, was recording the scene. Weston, on the other hand, was actually creating something new. In his work, subject is of secondary importance to the total photograph. Similarly, while the landscapes that I have photographed in Yosemite are recognized by most people and, of course, the subject is an important part of the pictures, they are not “realistic.” Instead, they are an imprint of my visualization."
That's not to say I disapprove of Photoshop or other image editing programs; sometimes, a bit of tweaking can help overcome a particular camera's weaknesses and provide an even more realistic final image than the camera can do on its own.