Issue link: https://digital.copcomm.com/i/13405
which made it into the film.” The majority of You Don’t Know Jack was shot on 35mm; greenscreen was shot on 35mm/24fps, as well as on HDCAM.According to Bair,“We shot HDCAM at 59.97 to match VHS sources,and we wanted to ex- actly match the motion and all the artifacting you would get when shooting interlaced.” Much of the greenscreen that was shot on 35mm was for “a tremendous amount” of driving shots done on a stage over the course of two days.The biggest challenge, says Bair, was shooting everything in ad- vance and matching angles. “A lot of those scenes took place in the late ’80s to the early ‘90s, and every character had gigantic eyeglasses.We had to make sure what we were seeing through the glasses was distorted in an appropriate way, even though it was shot on green. So there was a lot of manual tracking there to offset the backgrounds we were putting in.” How different is it shooting HDCAM as opposed to 35mm? According to Bair,“There are some general rules we follow in terms of how bright the green should be, but generally when shooting HDCAM, we are more concerned about the foreground subjects and making sure we are not blowing anything out and not overexposing the background.” What concerns Bair most is that HDCAM is a less forgiving format if anything is overexposed in terms of keying.When working with film, Phosphene makes sure the background isn’t overly lit,“but film has such a great response curve,we can deal with those issues much better in post if they happen to occur.”Thank- fully this didn’t happen on You Don’t Know Jack. In terms of trends, Bair says that because of how far software has advanced in recent years, the key is matching lighting,“and worrying a little bit less about perfect, ideal keys because the software can handle sub-optimal greenscreens. The software can work around limitations you have at the time; it’s much more about planning the shots in advance, and story- boarding is always a great idea.” With DSLRs becoming more commonplace in production, it was only a matter of time until they found their way onto greenscreen shoots. Phosphene has been working on Vanishing on 7th Street with di- rector Brad Anderson. Global Expertisecombines 3D matte paintings and live action. Ntropic directed and supervised the shoot. challenge, and that is maybe the biggest difficulty with it. You can also have a little aliasing just due to the way it’s capturing images, and it’s basically removing lines of data to go to HD from the full sensor size. So if you have very sharp images you can get a little bit of aliasing.” They have found that some software is able to com- pensate for HDCAM compression, and that going through the same process with DSLR helps in terms of doing an initial pass, which will remove some of the ar- tifacting before pulling a key. GREEN & BLUE Simon Mowbray, creative director/visual effects su- pervisor at SF’s Ntropic (www.ntropic.com) feels the biggest challenge when working with greenscreen, bluescreen or any processed background, is that budgets are tight, shooting schedules are compressed, and there isn’t always enough time to light the green- screen properly.“We always supervise shoots,” he says.“Almost every DP I’ve worked with knows how to light a greenscreen; that’s not the problem. It’s more that often there isn’t the luxury of time to fi- nesse the processed-background lighting, because ob- viously the foreground takes precedence.” Ntropic has also worked with DSLR cameras re- You Don’t Know Jack: HDCAM was used to shoot Al Pacino on greenscreen. He was then composited in. “We are doing tons of effects for that; and we’ve shot a ton of greenscreen elements with the 5D Mark II,” says Bair. “It’s amazing in many ways, if you know its limitations. It’s a compressed format, which is always a cently. Mowbray says that while there are limitations to the format, there are also benefits. “The Canon 5D’s H.264 compression can be a challenge for key- ing. Regardless, it still shoots a beautiful picture, which is half the battle. Also, its ability to shoot such a nar- row depth-of-field can be used to smooth-out green- screen unevenness. Even so, I still prefer to work with the higher-resolution formats for compositing.” He likes the Genesis when shooting digital and is eager to see the new Red cameras, but “film can be better in some respects,” he says.“You have more latitude.” When working with greenscreen, Mowbray and Ntropic recommend to DPs that they shoot it at key or as much as one-stop below key for film.“With blue- screen it’s as much as one-and-a-half to one-and-two- thirds below keylight level.Whenever we shoot digitally we make sure all the sharpening filters are switched off, so even though the footage may look a little less sharp on-set, the composite edge will be a lot cleaner.” For a recent Franklin Templeton spot out of agency Collaborate, Ntropic was called on to produce and post the greenscreen-heavy Global Expertise, which was directed by Ntropic creative director/founder Nate Robinson.The project is a combination of live action and 3D matte paintings. It features actors cap- tured against greenscreen and pictured in cities around the globe — the CG environments were cre- ated in-house at Ntropic. The viewer sees people in front of icons repre- senting these international locales, such as a pagoda (all CG), the Eiffel Tower, a rickshaw, the Sydney Opera House and Big Ben.These elements were ei- ther shot over greenscreen, or sourced as stock, and then integrated into 3D matte paintings. In the Big Ben shot, the uneven sky was used as the bluescreen.“It was a combination of rotoscoping and pulling keys from the sky,” describes Mowbray. “However, the flexibility of today’s software makes guerrilla compositing possible and believable, just with a longer turnaround.” A more traditional bluescreen shot is where a newswoman is pictured on a screen below a stock sticker on the side of a building in India. She was shot bluescreen and composited in.A complicated car shot was done greenscreen.This was a matter of “pulling keys through glass, which is always tricky,” says Mow- bray.“We ended up having to add reflections back into the glass of the car, and the background was a big 3D matte painting [of Sao Paulo]. All the reflections in the windows were added as a 3D element, which is a big part of compositing now.” Ntropic called on Autodesk’s Inferno, Flame,Toxik and Smoke for the piece.They also used Autodesk’s Maya.“We have a really solid pipeline between Maya and Inferno in that we use the 3D capabilities of both, which is an unusual way to use the Flame/In- ferno suite,” he says. Greenscreen/processed background is a great tool, sums up Mowbray. “In years past you’d almost always shoot greenscreen locked off.That’s really not the case anymore.The tools are such that it is much easier to build 3D worlds. If the camera has to move or dolly or crane, it’s not such a problem for us to build a 3D matte painting to make a world that works in 3D. It’s a lot easier for us to build a dimen- www.postmagazine.com July 2010 • Post 21