Blending human actors with digital beings presents on-set and post challenges. In the last Narnia film, faun legs were used on-set (above). This time the cast wore blue tights that were digitally replaced in post.

The weak U.S. dollar didn't help either, with Adamson commenting that "it's hard to shoot anything in L.A. these days -- it's so expensive. We did all our stage work in the Czech Republic."

Another factor that helped push Caspian's post-production across the Atlantic was of all things, the L.A. traffic. "When I was making my first film in L.A., I lived in Silver Lake. My composer was in Venice, Rhythm & Hues was in Marina Del Rey, Sony was in Culver City and the studio was in Glendale -- I was spending hours a day going from place to place. In [London's] Soho everything was a five-minute walk."

Dean Wright, The Lion, the Witch and the Wardrobe's visual effects supervisor and second unit director returned for the second Narnia film. Because of Caspian's scale, a second effects supervisor joined the project: Wendy Rogers, a colleague of Adamson's dating back to their PDI days. "Dean was on the last film and Wendy an addition on this one. I've worked with her a number of times over the years. Dean is from a production background while Wendy has more of a digital effects background. It meant I could let more go this time in terms of the digital side of things."

As with any film, blending human actors with digitally whipped-up fantasy beings, filming presented on-set as well as post-production challenges. "We had a lot of people in blue tights," Adamson says, "and on power risers -- stilt things with springs on them. They're used for circus acts. Wendy actually discovered them -- all the centaurs wore power risers [to bring them up to centaur-eye level].

Adamson says the most complicated shots to handle were the ones that went through multiple effects houses. This shot features the badger Trufflehunter.

"On the previous film we used some faun legs [on set] that kind of worked, but we really didn't use them enough to warrant them. We didn't have many people in fur pants this time -- just people in blue pants. It's a painstaking process [to patch together or replace actors with creatures], especially when you have these crowd scenes. It's a constant thing on set, asking people from the facilities -- 'do you really want people in this shot or not -- do you want to replace everyone or just put [animal] legs on people?' It's always a balancing act when you make that choice. Sometimes you leave people in and wish you hadn't. In some cases, they actually remove the people entirely and put CGI [creatures] in instead -- it's easier than putting the [digital] legs on them and tracking the actors. Sometimes the centaurs were fully CG, sometimes they were a combination of a real horse and a CG person.

"[In Wardrobe],we designed armor for the centaurs so the effects houses could create clean joins [between horse and human]; we decided not to make it easy for them this time. In the last film and this one, we really wanted to find that right balance between human body and horse body, how they belonged together and then how they moved. When a person rides a horse they're moved by the horse. The centaur is thinking and the horse body is moving with those thoughts. It becomes quite challenging." Adamson laughs when recalling one shot where a centaur is seen running with a human-style pumping arms motion: "Wherever possible, I would put swords in their hands to prevent them from doing that."

He estimates that some 1,000 Narnian creatures appeared onscreen, of which only 150 were real people onset. "We had 300 real Telemarines [the enemy army the Narnians are battling], which we turned into 5,000" via motion capture and motion control cameras. "You put your 300 guys close to the camera and then extend them from that point out."

Adamson says the most complicated shots to handle were the ones that went through multiple effects houses. "The live-action plates were augmented by Weta with backgrounds that had some characters from the Moving Picture Co., which were then finished off with [the lion] Aslan and [badger] Trufflehunter by Framestore. I think three vendors were the most we got to in this one.

"I edited the film in hi-def. I had a big screen in the edit room so I could watch scenes as the audience would view them. There were times I told myself: 'I don't need to be in a close-up here.' That's helped to give film a greater expanse."