Sam Raimi, director of cult horror comedy The Evil Dead series and Spider-Man trilogy, loves the movie The Wizard of Oz so much that he has directed a film about it.

Oz the Great and Powerful, to be released on the mainland on March 29, is Raimi's cinematic prequel to the 1939 tale loved by both adults and children.

"I've always loved emotional movies that have an effect of uplifting the audience, making them feel positive and giving them energy," he says in Beijing recently.

Deep in his heart he wants to make films that make people smile, feel joy, and that remind them of what it feels to be loved.

But he had to start his career with independent horror movies because he had no other choice.

"I wanted to make comedies and dramas," he says, "but to break into the movie business when you only had a little bit of money, the only kind of movie the theater would show is horror movies.

"Because I had the experience with my favorite movie The Wizard of Oz, I always wanted to make a movie like that, to try a similar effect on the audience that movie had on me."

Raimi's Oz film looks at how the wizard became who he is.

James Franco, who worked with Raimi in the Spider-Man trilogy as Harry Osburn, portrays Oscar Diggs, a circus magician with dubious ethics. Reluctantly drawn into the epic problems facing the Land of Oz and its inhabitants, Oscar transforms himself not only into the great and powerful Wizard of Oz but into a better man as well.

"It's the tale of how an average man who was selfish became a great wizard who is selfless," says Raimi.

Raimi believes Franco is the right choice after observing the actor's growth over years, which resonates with the protagonist.

When they first met in 2000, Franco impressed Raimi as a great actor but a little conceited and selfish. When they made Spider-Man 2, Raimi found Franco to be a better listener and was more giving. By the time the third Spider-Man movie was made, Raimi saw him developing a soul and becoming a more mature man.

"What is interesting for me is to watch the whole progression of Franco to a much nicer, opener and more mature professional actor," he says. "That's kind of what the Wizard goes through in our movie. If James could recognize what he has been through in life, how he has changed, and who he is now, he can sympathize and put it into the performance."

The film is Raimi's first foray into 3D technology. To better introduce the audience to the fantastic world of Oz and give them a sense of dimensionality, he designs a special 18-minute long opening for the film.