24 producers turned L.A. into Washington D.C. digitally, using Stargate Studios to create backdrops of the Washington Mall, the backdrop of the inauguration. Courtesy of Stargate Studios. © 20th Century Fox Television. 

After 18 long months off the air, 24 finally returned to television for its seventh season on Sunday with a blistering two-night, four-hour premiere. For its first six years, 24 took place and was shot in and around L.A. But coming off a disappointing sixth season, FOX and the 24 series exec producers decided it was time to look for a way to freshen up the series by giving former CTU agent Jack Bauer (Kiefer Sutherland) a new backdrop to fight domestic terrorism.

The creative team decided it was time to throw Jack into the middle of the political epicenter and set season seven entirely in Washington, D.C., despite primary production remaining in L.A. But before the WGA strike delay in late 2007, the 24 team went on location for the first time ever to the nation's capital and spent two weeks there shooting material for the first handful of episodes for the year. When the strike started, FOX then decided not to start airing the half-produced seventh season scheduled for January 2008. They instead decided to delay the season until January 2009 and ordered a two-hour network movie title 24: Redemption (which aired last November) to serves as a narrative bridge between the long gap in season. Showrunner Howard Gordon set the movie in the fictional country of Sengala, Africa, and in Washington, D.C. on the Inauguration Day of new President Allison Taylor (Cherry Jones).

With a tighter budget, 24 didn't have the luxury to return to D.C. to get additional location shooting for the TV movie or the back nine of the season, so the producers decided to go virtual, utilizing visual effects to make L.A. work as D.C.

24 producer Paul Gadd is the man responsible for the in-house visual effects coordination, planning and production with such outside visual effects vendors as Stargate Studios, Eden FX and Look Effects. While 24 isn't known as a show that relies on vfx sequences, season seven's change of location has amped up the inclusion of more digital wizardry than ever before.

"I think we have had a lot more visual effects this year," Gadd assesses. "Because of D.C. we have done a lot of visual effects adding, but maybe not as much as you might think. In fact, we now think we should have done it more often because it's so simple and works great. But we really didn't want to make the season about finding a place to put a monument, but more about the scene itself."

Instead, Gadd says vfx shots have really been judiciously considered to get the most bang for the visual buck. "We knew we were going to need to design shots where we could add D.C. monuments that really sold the fact we were in D.C. We're outside a lot running around on 24. The intent was generally that we didn't want a big shot where we are really framing up the Capitol in the foreground, but rather to put things in the distance. It wasn't to hit it over the head with that: 'Hey, we are in D.C.!' but where we could, to place things in the shot. There are upcoming episodes that specifically call for certain things, like one where [a villain] is revealed. It was scripted that he is on the opposite side of the Potomac looking at the night view of D.C. so we shot the actor out in Long Beach just looking at black."

Stargate Studios in Pasadena, California is known for their greenscreen virtual backlot composite work on a host of such primetime series as Heroes and Grey's Anatomy, and Gadd says their experience was a perfect fit for 24's needs. "One of reasons we went with Stargate Studios is because they have a library of things in D.C. that they have shot. We knew they had this library and we could take advantage of that as opposed to having to shoot whatever we needed. Of course, they didn't have everything we needed," he continues. "There were a couple of instances, like the shots across the river they didn't have, so we looked at stock footage. But it turned out that someone who worked with us on the show a couple years ago was going to D.C. for a film festival. He said he had a camera and asked if we needed anything. I said, 'As a matter of fact...' And there is another scene where a car is parked by Lafayette Park. He picked those shots up for us and Stargate composited them. It was fortunate that it worked out."