Consider an HDTV flat panel — perhaps the one you've been eyeing at the local electronics store. Sporting a 16:9 aspect ratio, 42" diagonal viewing area and crystal clear images, it's one impressive example of modern entertainment technology. But now, imagine an even larger flat panel, in full 1080i HD resolution, stretching almost 70' across the stage.

On November 3, Radio City Music Hall opened the 73-year-old Christmas Spectacular with a new addition: the world's largest moveable HD resolution LED wall, with LED tiles and custom engineering provided by Barco.

There's nothing small about the Christmas Spectacular, and there's nothing so big in the production as the new HD screen, which is tucked into a narrow footprint at the very back of the stage. Forty feet tall, 70' wide, and comprised of 2.5 million LEDs, it's the world's largest and heaviest indoor flown screen of its type, weighing 45,518 lbs. A total of 1,600A of electric power was also installed, a portion of which has been allotted to future expansion of the screen's capabilities.

“It's the largest single project Barco has ever done,” says Ken Van Antwerp, senior project manager of Barco Media LLC in Logan, UT. Work began in earnest in July, when the 1,269 individual Barco ILite 10mm tiles that comprise the screen were assembled in China and then shipped to New York for design, construction, testing, and adjustment. The fast-track installation process of the tiles and their aluminum frame was shoehorned in between summer concerts and events and completed just two weeks before the show's premiere on November 3. “About 30,000 nuts and bolts hold the screen together, which hoists up and down and hangs like a curtain,” says Van Antwerp.

The video system that drives the LED wall consists of six Barco D320 PL Digitizers, fiber optic transceivers, and a high capacity HD playback server. All video and computer effects are generated in 10-bit, 4:2:2 1080i HD format at facilities of Colossalvision, the primary video consultant for the project. In the “engine room” several levels below the stage, video files are stored in uncompressed HD on 3.5 Terabytes of RAID storage and routed to the six D320 Digitizers for playback.

The wall itself is divided into six video “slices,” each of which is fed by a digitizer in DVI format. Fiber optic links convert the D320 output to/from DVI, for the long cable run from the engine room to the wall. The show's overall sound and image playback is a complex hybrid of automated and manual events. Timecode video playback cues can originate from various locations, such as the theatre's main audio console or even the lighting board.

“It's a timecode-aware system,” explains David Niles, director/DP/designer for Colossalvision, “but it's not the way that you would typically automate a show. Instead, we've merged the video into a very complex theatrical machine that already runs fine. Normally, in the video world, you would never sync video playback to audio cues, but here, the HD server listens for cues that might originate from the audio board or other locations.”

Finding a proper place for the video wall was a major issue as the screen concept took shape. “It's on a counterweight system, so the facility had to be strengthened to accommodate the weight,” Van Antwerp says. “And the envelope we had to work in was very small. The depth was the challenge. Despite its size, the screen is only a foot deep, and it comes within three or four inches of catwalks that stick out from the top of the back wall.”

Technology left over from the first crop of Rockettes back in 1932 gave the installation team a lift. “There's an original arbor system 3' off the theatre's back wall that I walk past every day but had never found a use for,” says Rich Claffey, Radio City VP of event production. “It had been used for what they called the old light cyc. It wasn't quite sufficient to lift the weight we needed, but I felt we had hit paydirt and could save huge amounts of money. I immediately made room for the screen in the grid, which was no small undertaking because of all the stuff that's accumulated there over the years. We'd never cleared a path for something this big before. I added a master arbor and used the original system as helper arbors to lift the screen up and down.” Scenic Technologies president Fred Gallo, Claffey's old friend and mentor, consulted on the rigging and installation.

From a production standpoint, the LED wall opens up worlds of creative possibilities. For the Christmas Spectacular, traditional numbers have been enhanced with virtual content that complements but does not overwhelm the lower-tech mainstays of the show, including versions of “The Nutcracker” and “The Parade of the Wooden Soldiers.” Digital imagery augments the Rockettes' makeover of Radio City into a winter wonderland during “Deck the Halls,” then accompanies Santa on his rounds toward the close. Most dramatically, the video wall is used to replace an old gag, formerly performed with cumbersome, hard-to-clean plastic mirrors, where several dancing Santas onstage multiply into dozens more onscreen. “That's all I talked about this summer — dancing Santas, dancing Santas,” Claffey laughs. “I thought we could pull it off without mirrors. When my kids saw it, they said, ‘Do you mean that's a screen?’”

“It's all about the visual,” says Niles, “and when you see it, the pictures are amazing. It creates what I call a ‘whoa’ moment, where suddenly a stage that is 60' deep appears to be 300' deep. We've created multiple illusions that give an entire new dimension to the Radio City production.”

For next year, the Radio City team is dreaming up new uses for the new technology, like rendering the star drop during “The Living Nativity” sequence in HD. Once the show wraps in January, producers are already lining up to take advantage of the new Barco LED wall; a Chinese TV station is using it in January. “There are a lot of independent producers that suddenly want to do shows here,” says Niles, “because this new technology is now available, installed, and ready to go.”

Paul Berliner is president of Berliner Productions in Davis, California, a company providing video production and marcom services to the broadcast and entertainment industries. He can be reached at

Robert Cashill also contributed to this article; he is a freelance writer living in New York.