Movie spoilers below:
Normally after reading the book first and then watching the movie afterward, I always give the movie a fair chance. But not this time. For whatever insane reason, the movie makers left out two very important scenes. The first one was a stunt, with Robert Langdon jumping out of a helicopter using the helicopter windshield cover as a sort of parasail and landing into a river. A corny and unbelievable stunt I realize, but one that shouldn't have been left out of the movie simply because it was death-defying.
Most important was the second scene, which was a plot element. I could have lived without the stunt scene, but this one was the culmination of the air, fire, water, and earth ambigram branding scenes. It was a perfect diamond with all four elements combined together into one big ambigram on the final brand, not some cheesy double-cross (pardon the pun) design which was shown in the movie.
Btw, I like Tom Hanks as an actor a lot, but I think he might have been a little out of his element in
The Da Vinci Code, and
Demons and Angels.
These movies may have faired better had the adaptation from novel to big screen not been so poorly executed.
This is what the final brand should have looked like in the movie; if you turn it upside-down it will still look exactly the same: