From the National Catholic Reporter interview: (HT: Sept/Oct 2012 Bulletin of the New York C.S. Lewis Society)
Have the Narnia films helped or hindered our understanding of Lewis?
Lewis didn't expect his books to survive long after his death, so he would have been surprised by the films, as would Tolkien. As for the films themselves, these lack subtlety and have too many special effects. I think [director] Peter Jackson did a much better job with The Lord of the Rings trilogy, combining a vision with great talent. Whereas Jackson generally stuck to what Tolkien wrote, the Narnia producers just changed the stories as they wished.
I was consulted, especially about the character of Aslan. It was always Lewis' proviso that Aslan must be handled very carefully. He represents the Son of God, so you can't blaspheme with him. I've read many screenplays of The Lion, the Witch and the Wardrobe, however, and almost all have portrayed Aslan as a comical character. Lewis would also have disliked the way human persons are placed inside his animals. He'd seen Walt Disney's Fantasia and would have been thrilled to see what can be done now with computer-generated images. But it's the scripts which always let us down. They should stick to what Lewis wrote, as with Shakespeare.
I agree with Hooper.