Ansel Adams developed the Zone System of photography, later adopted by many photographers and taught in photography schools and workshops.
This little article is oversimplified, but one may obtain a basic understanding of the system here: Zone system
Using this system, one tries to capture the best image possible on the negative. Choosing the best tonal scale demands an artist's eye. The rest depends upon darkroom artistry. Adams was a great artist.
This article mentions the matrix meter. Exposures might approximate the zone system, but it still must be the photographer who determines just what tonal values are emphasized, and what changes must be made during the preparation of the final print image.

The techniques, of course, are applicable in digital photography, but it is the mind of the photographer that supervises the computer and tells the machines what the final image must be.

Sometimes the image must be captured NOW, such as the Moonrise shot or some others mentioned above. The negative may not have the perfection of a carefully pre-planned shot; the photographer must achieve his final result in the darkroom (or through the computer, scanning, etc. methods available today). I know a professional photographer who uses them; his equipment and programs are the best and cost a small fortune. He admits, however, that he lacks the ability and creative imagination of Ansel Adams.