American Cinematographer - September 2010 - 14

Christiaansen (top) and Steadicam operator Ari Robbins (bottom) capture some of the onfield action against a greenscreen backdrop.

shooting a soccer field in Glendale, Calif., as a stand-in for a World Cup stadium. The athletes played against huge greenscreens in some shots, and in others the camera was pointed down at the field from a high angle to keep the horizon out of the frame. Christiaansen and Steadicam operator Ari Robbins filmed from the ground or from the back of a golf cart as it zipped around the action. “It was critical that we show off the range of the camera as far as how much shadow detail you can get while maintaining a clean black, all the way up to how it handles highlight details when
14 September 2010

it’s overexposed,” notes Christiaansen. “During the daytime soccer scenes, we went with hard sun and no fill. We just let the camera deal with it.” (A few 4K HMI Pars were brought out to the field but weren’t used.) ND.6 and ND.9 filters were stacked onto a base ND1.2 to keep the Optimos and Master Primes around a T4. According to Nicholson, pulling keys off daylit bluescreens or greenscreens can be a nightmare at ISOs over 250 because of grain, especially when recording video, but on the Alexa demo, “the greenscreens worked like a hand in the glove. One of the
American Cinematographer

defining factors of a digital camera is how fast you can work with the recorded material on a demanding post schedule, and all of the visual-effects artists at Stargate thought the Alexa material keyed beautifully, even with lots of motion blur at ASA 800! That’s a great advantage for shooting greenscreen visual effects.” The first day of filming was scheduled as a two-camera shoot, but the second Alexa didn’t show up until the next night. When it arrived on set, at 10 p.m., it was out of its flight case and ready within 15 minutes. The opening images of the test film were shot at night in downtown Los Angeles, near and beneath the oftphotographed 6th Street bridge. In one wide shot, the L.A. skyline glitters. In another, the moon glows huge and cool in the sky as the blinking lights of aircraft cross a crisp, clear frame. “We also had to demonstrate the Alexa’s low-light sensitivity, great low-light color rendition and good blacks at ISO 800,” says Christiaansen. Arri made as many of its grip-and-electric resources available to the production as possible, but Christiaansen and gaffer Paul Samiango didn’t need the power of a 10-ton grip truck to light up an entire street — in fact, they probably didn’t even need a 5-ton truck. “We ended up using four or five 400watt Pocket Pars running off battery blocks!” says the cinematographer. Even a 1.2K HMI called for every scrim and bit of diffusion they could jam onto the lamp head. Aside from the Pocket Pars and a scrimmed-down 2K Fresnel hung from the bridge, most of the ambient light was provided by existing streetlights. For the shot where the bridge splits in half to bathe the players with sunlight, a 2K Xenon spotlight was hung from a Condor just 15' from the actors to create a huge overexposure that would demonstrate the Alexa’s latitude and highlight characteristics and help transition from the night bridge to the fantasy world of a World Cup game. “In the night sequence, it helped that we were looking for a raw, sketchy light design,” notes Christiaansen. “We wanted the actors to move in and out of a single light source so we could see the camera handle extremely underexposed areas.” The Alexa’s workflow was designed

American Cinematographer - September 2010

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