Fries originally converted 24 cameras for Aardman, but halfway through the shoot for Chicken Run Barnes had to order five more units to keep up with the demands of production. The filmmakers used Canon K35 prime lenses (in sets of 25mm, 35mm, 50mm and 85mm), which were specially converted in Japan for close focusing. These were used in conjunction with Cooke 18-100 T3 zoom lenses and one 25-250mm T3.7 Cooke zoom. Barnes offers, "In the studio, we traditionally stick to the Canon primes, as they are all reasonably well color-matched, have similar coatings and are contrasty to a similar degree. They intercut pretty well with the Cooke zooms without significant grading problems." For wide shots in tight corners, the production made use of two 14mm Canon still-photography lenses converted with BNC mounts. The film was shot in the 1.85:1 aspect ratio. Rigging, supporting models and the edges of sets were just on the edge of the framing area, meaning it could not be shown in a deeper format, according to Barnes.
The crew made considerable use of motion-control rigs on Chicken Run. The filmmakers used Mark Roberts’ Milo motion-control platform on tracks, which provided the absolutely accurate repeatability that the 3-D animation required. Riddett says the rigs were capable of all the movements he wanted. Their ample vertical range is evident in the film’s opening nighttime sequences, which also exemplify another Aardman trademark: the ability to create a sense of mystery through extreme contrast. "We particularly wanted a lot of dark shadows, just to see how far we could get away with [establishing] a sense that you are not quite sure where you are," Riddett notes. "[We let] you see details such as dark shadowy forms behind huts or barbed wire. You can’t quite see the characters at the outset they are simply seen in silhouette." To achieve the necessary depth of field, the Canon primes were stopped down to between T11 and T16 for the majority of the shots, an atypical use for these fast (T1.3 or T1.5) lenses; they were also employed much closer to the action than they were originally designed to be.
The physical scale of the puppets has an important bearing on the animation itself. In 3-D animation, if a puppet is too small it is generally difficult to achieve fine detail, particularly in expressions; if the puppet is too big, there is too much Plasticine to move around to animate faces effectively. On Chicken Run, Aardman’s animators mainly used two scales. For the majority of shots, the chickens were 9" high and the humans 12"; in shots featuring distant characters, the chickens were smaller. Chickens and humans were seldom in the same shot, and when they were, the humans were used in the foreground and small-scale chickens were used in the background.
Many of the film’s sets were built in perspective to enhance the effect of distance. For the opening sequence, in which the farmer kicks a gate shut on the hapless chickens, only a very large-scale boot and part of the farmer’s leg were used in the shot to complete the illusion. Seen in this context, Aardman’s attention to the technical minutiae of its equipment-engineering has been vital in order to convincingly translate its small puppets to the big screen.
Most of the film was shot "double frame" that is, with two identical frames of each character pose shot consecutively, allowing animation of the character 12 times per second rather than 24. To speed up the process even further, assistants made a set of different mouths in different phonetic shapes for each character in advance; these were substituted as required and blended into the face.
Chicken Run required an unusually large team of animators, and Aardman set up an intensive six-month animation course, in collaboration with the University of the West of England, to prepare them. Loyd Price, the supervising animator on Chicken Run, was heavily involved in the training, making sure everyone had the Aardman "feel" and nurturing their skills to ensure that any of them could work on the same character without the changeover being noticed. "Our philosophy," Lord says, "is that the animators are not just a pair of hands, they are performers. What we are looking for is the best of the director and the best of the animator together. Very rarely do we have to tell the animators not to do a certain thing or not to follow their instincts more often, their instincts are inspired and helpful, and sometimes they’ll come up with a great idea that completely makes the shot."
Ironically, two of Aardman’s most experienced animators, Lord and Park, were too busy directing to animate on Chicken Run, and they were also left with little time to storyboard. To help the filmmakers, DreamWorks sent two storyboard artists, David Bowers (who served as storyboard supervisor) and Rejean Bourdages, over to Bristol to work on the production.
Like all animated films, Chicken Run relies heavily upon sound design. After a 20-month shoot, the team finished up in postproduction at De Lane Lea Sound Centre in London. It was an unusual job for the facility, which is more accustomed to working on live-action features that already have at least the voices and some sound effects in place. On Chicken Run, all the sound team had were the voice tracks recorded by the cast at the outset (or subsequently re-recorded individually) in a studio.
Technicians at De Lane Lea were amazed to be working on such virgin audio terrain, and Lord was surprised at the number of sound layers they managed to build in to match the visual detail achieved by Aardman. These sounds ranged "from a creaking gate to a rustling tree, every touch of flesh on flesh, even knuckles cracking," says Lord. Scenes such as those set inside the chicken-pie machine are remarkably reinforced by the recorded tracks.
Of course, the film’s puns and allusions stand alone and represent yet another level in this multi-layered movie, though some of the jokes might not play in every country. The directors are confident that the film’s referential gags are universal, but they were still careful not to hang essential plot points on the verbal gags. As Lord concludes, "In a sense, they are throwaway lines if [the audience] gets them, great; if not, they are none the poorer."