Production

Background

In 2003, 3-D film production company 3ality Digital released a new type of 3-D filming technology, created by film producer and 3ality co-founder Steve Schklair. The technology used motion control photography and real-time image processing to create a realistic 3-D experience without subjecting the viewer to motion sickness, and was intended to be used as an inexpensive and effective way to film live events in 3-D, such as concerts and sporting events. With the help of 3ality co-founders David and John Modell, former owners of the Baltimore Ravens American football team, the 3-D technology was initially tested by shooting several American football games during the 2003 NFL season, including Super Bowl XXXVIII. The footage was shown to the National Football League, with the hopes of creating an NFL-based 3-D IMAX film. While waiting to hear from the league, 3ality executives Jon and Peter Shapiro proposed the idea of creating a 3-D concert film, after having produced the 2-D IMAX concert film All Access in 2001. While All Access featured performances of several artists, the 3ality team felt it would be best to create a 3-D film focused on one live act, and they chose their favorite live band, U2.

John Modell previously worked briefly with U2 in 1997, after he and his brother David became interested in featuring LED video technology at Ravens Stadium at Camden Yards. At the time, the first and only LED video screen in existence was being used by U2 on their PopMart Tour, so Modell toured with the band on and off for a period of six months to learn about the technology. During that time, he became friendly with the band's art director, Catherine Owens, who had worked with the band since their Zoo TV Tour in 1992.

Peter Shapiro contacted Owens in 2004 to propose the project to U2. Owens became interested in the project after viewing test footage of the 3-D technology, and expressed interested in directing, despite not having any previous filming experience. Before the band agreed, test footage was filmed with a single 3-D camera at one of U2's Vertigo Tour concerts in Anaheim, California. As U2 had previously experimented with video technology in the past, the band was interested in the 3-D film project as a technological experiment, rather than to make a profit. Once the footage from Anaheim was shown to the U2 organization, the band agreed to participate in the project, and officially signed on in mid-2005.

Filming

The producers originally wanted to shoot the film in and around Los Angeles, California, where 3ality Digital's headquarters were located. However, Bono insisted on shooting the film at the concerts in Latin America because he felt that the passion of the audiences in those countries best resembled the passion of the audiences in the band's home of Ireland. U2 toured Latin America on the fourth leg of the Vertigo Tour in February and March 2006, with eight shows in five cities. The fourth leg of the tour featured eight shows, all of which were filmed for the movie, minus the first show in Monterrey, Mexico. The film's production featured the first ever 3-D multicamera live shoot, and was shot using every digital 3-D camera and recording deck in existence at the time.

The crew only had two days to set up the filming equipment before each concert, which required running fiber optic cables and hooking up an electrical generator to supply power at each venue. The digital 3-D filming equipment consisted of nine custom-built stereo camera rigs designed by camera operator Vincent Pace and film director James Cameron, known as the Pace/Cameron Fusion System. Each of the nine camera rigs included two Sony CineAlta F950 cameras fitted with Carl Zeiss digital zoom lenses, which captured video onto HDCAM SR recording decks. The two cameras on each rig acted as a pair of eyes to help create a 3-D effect in post-production. A total of 18 cameras were used in filming, each of which averaged a weight between 200–300 lbs (90–136 kg), requiring the cameras on each rig to be welded together. The film's setup also included the first ever spydercam utilizing the Pace/Cameron Fusion System. Five operators were required to work on each rig at a time to ensure that the focus on both cameras on each setup were synchronized at all times. During the filming period, one of the cameras was destroyed by water, and the remainder of the cameras were later waterproofed. Since Owens had no previous filming experience, she was involved with every aspect of the film except for the live shoots, which were directed by Mark Pellington, who had previously directed a video for U2's song "One."

The concerts were filmed in a style which Owens described as "very unorthodox", without using storyboards or shooting scripts to capture realistic, unstaged footage of the band's performances. The shoots were clearly planned so that the filming would not interfere with the band's performance or the audience's view. To avoid capturing footage of other camera rigs, the crew would switch off each night filming either left-to-right or right-to-left, or film entirely from the back of the stage. Since several different shows would be edited together to create one performance, the band was required to wear the same clothes each night to eliminate continuity errors in the final cut of the film. Lighting for the shoots involved the same lighting used at all the regular concerts, except for the additional spotlights focused on the audience. The audio for U2's performances was recorded using microphones placed on the main stage, and around the two B-stages, where the band would perform during several songs. To record the audience, additional microphones were placed in various locations depending on the type of venue in which the band was performing. Originally, 96 different audio channels were used for recording the band's music. The audience microphones that were added extended the total to 110 channels.

Shooting began in February 2006 at Estadio Azteca in Mexico City, where two shows were filmed exclusively to capture medium shots. At the following two shows, at Estádio do Morumbi in São Paulo, Brazil, two cameras setups were used to capture long shots. The band's next concert, which was held at Estadio Nacional de Chile in Santiago, Chile, featured only a single overhead camera setup, used to capture footage of drummer Larry Mullen, Jr. Prior to U2's two concerts in Buenos Aires, the band performed a 10-song set at River Plate Stadium with no audience to capture close-up shots using a wide-angle lens, which Owens dubbed as the "phantom shoot". During the following two nights in Buenos Aires, the concerts were filmed with all nine pairs of cameras, capturing shots of the band from the B-stages. The Buenos Aires shoot was the largest of the project, and required a crew of 140 people.

In March 2006, the Vertigo Tour concerts were postponed after The Edge's daughter became ill. During the interim period, the footage from the seven filmed shows were put together, causing the crew to realize that several elements of the film were still needed, such as shots of the stage's video screen and the concert audience. When the band resumed their tour on its fifth leg in November 2006, an additional two shows were filmed in Melbourne, Australia at the Telstra Dome. Two camera setups were used for the final shoot, including a twin-camera system that was used at the previous shows, and a single CineAlta camera with a steadicam, used to capture close-ups of the band. Because the ladder setup used only a single camera, its footage was filmed in 2-D and would later be converted into 3-D during post production.

Editing

Editor Olivier Wicki was chosen to work on the post-production of the film, after previously working on U2's "Original of the Species" music video. Wicki worked closely with director Catherine Owens during the post-production process, developing ideas for each track before editing the footage. Over 100 hours of footage was filmed featuring performances of 26 different songs. To make the film appealing to a mainstream audience, Owens decided that only 14–15 songs out of 26 would appear in the final cut, most of which would be U2's most popular songs. When selecting songs for the film, the crew had to ensure that the performances of each track fit in with one another. For example, the band wanted their performances of "Mysterious Ways" and "Until the End of the World" to be included, however they were left out since they felt that those songs were out of place with the rest of the film.

Eventually, 14 songs were chosen to be in the final cut, and the footage was edited in 2-D using Avid systems, over a period of eight months in New York City. Video post-production continued in Burbank, California at 3ality Digital's 20,000 square foot (1900 square metre) 3-D production facility, which had just recently opened prior to the completion of the filming. Wicki worked with 3ality Digital to create the film's 3-D and CGI effects. Footage was edited into 3-D using software that was created by developers at the same time the film was being shot. Many of the scenes featuring several band members were created by layering several frames of footage on top of one anot