Based on a Short Story by Stephen King

Plot
For the most part, I was really impressed with how well the movie plot stuck to the plot of the short story.  The biggest (and most crucial) aspects of the story remained constant: same major characters, Andy still broke out of jail and Red was still released, and almost all of the tangent stories Red narrates in the book are included in the movie, with the ever-so-soothing voice of Morgan Freeman to retell them.  With this being said, some differences still arose.  The first we are made aware of is that Norton is the warden from the start of the movie, as opposed to coming into the prison halfway through the story as in the book.  This is understandable for simplicity's sake, and nothing is truly lost as a result.  Another difference is that in the movie the alternate identity Andy has made for himself, Peter Stephens, was created to cover the Warden's tracks, and ends up being used to steal all of the Warden's money.  In the book, however, Andy's money is earned separate from Norton's, and Andy never takes the Warden's money.  Lastly, in classic Hollywood style, three characters meet demises unlike their literary counterparts.  Tommy Williams is shot by the guards (instead of being transferred), Brooks the librarian hangs himself (instead of dying naturally), and Warden Norton shoots himself (instead of simply resigning).  For a semi-accurate synopsis and hearty chuckle, watch Family Guy's Shawshank Redemption Parody.  It was a little too inappropriate to embed...viewer discretion is advised!

Point of View
I didn't really see any drastic changes in POV from the book to the movie.  In the book, the narration is first-person singular, and the story is told through Red's perspective.  In a movie it's difficult to show first-person all the time, but the story is still narrated by Red and he features prominently in the movie.  The only character whose thoughts we are able to take into consideration are Red's, and his interactions with the other inmates define what we as the reader are able to take away from the movie.  There are few occasions where Red is neither present in the situation nor explaining what is happening on screen.  For instance, when the Warden takes Tommy Williams outside to ask him whether or not he'd testify for Andy and is subsequently shot for unsuspectingly saying yes.  There is a correlation between this scene not being described by Red and it also not being included in the original short story.  This is because the entire work is narrated by Red in first-person, and it simply wouldn't make sense for Red to truly know what happened to Tommy.  As a reader, I'm really smart for picking up on this.

Characterization
Although the movie left out certain minor characters who were in the book, this is not the most significant change in the way characterization presents itself in the movie compared to the book.  For me, the biggest change was the role of the character Brooks.  In the book, Brooks is briefly mentioned as Andy's predecessor in the library, the man who delivered books to the inmates before Andy arrived and became his apprentice.  In the movie, though, Brooks takes on a whole new persona.  He is first introduced Andy's first day in the prison, and feeds a maggot that was found in Andy's lunch to a pet crow that he keeps in his coat pocket.  Through much more detail and characterization, Brooks becomes a vital part of the Shawshank gang until he leaves in a dramatic fury involving attempted slicing of Heywood's throat (upon receiving his parole letter, Brooks thought killing Heywood was the only way to stay in Shawshank).  He hangs himself in a halfway house very soon after being released.  I enjoyed the added character depth given to Brooks, because usually characterization takes a backseat in movies, instead of vice versa.

Setting
As in the book, almost the entirety of the movie takes place in 'Shawshank Prison', located in Maine as a state prison.  The actual prison used in the film, however, is the Ohio State Reformatory in Mansfield, Ohio.  I liked the prison they used, too (as did my fellow moviegoer, Alix), because it had an older feel and definitely seemed enclosed and shut off from the world.  Not much changed during the transfer from book to movie, and it was easier to visualize the setting when I could see it for myself on screen.  It was almost disturbing at times, like when Andy crawls through a half-mile of sewage (puking on himself, mind you) to reach freedom in a small stream as rain and thunder crashes down.  The final scene, which is alluded to in the book but not stated outright, finds the two men reunited on the beach of the Pacific fixing up an old boat.  This scene fit right along with what I imagined for the book's setting, and goes back to one of the final lines in the story, expressed by Red, "I hope the Pacific is as blue as it has been in my dreams."

Theme
Because the movie followed so close to the book's plot, characters, point of view, and setting, it naturally follows that the same theme was conveyed through the Hollywood adaption of King's classic.  The one difference I could elaborate on is the character who received the central focus in the movie when it comes to theme.  As I said in my short story blog regarding the theme, Red was the main character who used Andy Dufrense as a launching pad for his own personal revelations on life and hope.  This meaning is harder to find in the movie, because even though Red still narrates the story, it is difficult to ignore the fact that all of the major action revolves around Andy.  The viewer is immediately drawn to his plight (an innocent man wrongly mistreated in a corrupt correctional facility) and makes the connection that he is the main character.  Andy's growth as a character is what is seen in the movie, and Red's narration serves as more of an outside passerby's look into Andy's life.  Because of this, I believe the filmmaker missed the mark when it came to the 'meaning of the work'.  Despite this, I still enjoyed the movie and respect its place as a classic in the hearts of countless American ex-convicts.