Here's Frank Darabont again, now hogging the "Director" section.
Yep, Frankie boy was so involved in every aspect of this film it's a surprise he didn't cast himself as both Red and Andy on top of everything else. (He probably thought better of it after he realized how primitive split-screen technology was at the time.)
Darabont was able to acquire the rights to the work in the first place after impressing Stephen King with his story-to-film adaptation of The Woman in the Room, another short story by the master of horror. (The short story was a very personal one for King, and he was impressed by how Darabont handled it in part for that reason.) So he'd already had a chance to show off his directing chops.
Unfortunately, Shawshank was one of those rare movies that got an Oscar nomination for Best Picture but failed to secure a nomination for its director. Which still kinda confuses us. The movie was sensational but the guy responsible for making it that way wasn't? We're still waiting for the Academy's Board of Governors to email us back and explain that one.