"If you look at that cave scene with Gollum, that's the biggest pay off for us creatively, that's where it all came together. Because there's less blur you perceive detail all the way though - you really pay attention to the nuances of Gollum's facial animation."
Letteri says that it's this realisation of digital acting that stands out as The Hobbit's crowning FX achievement. "Gollum was our one speaking character in the original LOTR; sure we also had Trolls, Uruk-hai and Orcs fighting battles but they really didn't have to deliver lines. In The Hobbit, in addition to Gollum, we have five other speaking digital characters.
"We've brought creatures off the page as Tolkien described them, in a way that ten or twelve years ago would have been almost impossible. The fact that Peter Jackson can write a nine minute scene with an actor and a digital actor together (the Riddles in the Dark scene) to me is a great testament to what you can do with the art form these days."
If you want to learn more, pick up The Hobbit Blu-ray says Letteri. "We go into deep detail about the visual effects," he enthuses, "really breaking down how the characters were created. Fans will get to follow the thought process that goes into the overall design through to how we created the final shots for the movie."
And what of the future? Joe Letteri doesn't believe the evolution in film making technologies is going to slow down any time soon. 'There's always going to be more we can put into the image," he says. He almost seems to be relishing the long nights ahead.
The Hobbit: An Unexpected Journey is released on Blu-ray April 8.