• Blogs
• Forums
• Tradeshows
• Partners
• White Papers
• Events

Building Collateral

Aug 1, 2004 12:00 PM, By Michael Goldman

Crafting a Viper-based Look

Sidebars
Digital Intermediate

Dave Canning recalls being extremely up front with director Michael Mann when the director first floated the notion of using the Grass Valley Viper FilmStream camera for his new DreamWorks film, Collateral. (For a look at an early use of Viper cameras on a smaller feature film production — Red Riding Hood — see “Once Upon a Time in Sylmar,” October 2003.)

“Michael had a specific creative look he was going for, and he felt HD was the best way to capture that look,” says Canning, a veteran digital imaging technician who has worked with Mann on several projects. “He suggested using the Viper instead of [a Panavised Sony HDW-F900 HD camera], mainly because Viper had the advantage of letting us capture squeezed, widescreen images without having to crop the picture, and because he liked the Viper's color imaging capabilities. But even right before principal photography, I told him I was positive we could make the movie he envisioned using the F900 cameras, but I wasn't sure we could do it using the Vipers. It was just too early for those cameras in a production setting. As soon as I told Michael that, he smiled and said, ‘That decides it then; we'll use the Vipers.’”

For a variety of reasons, the movie evolved into a multimedia affair involving 35mm material, HDW-F900 material, and Viper material. While 75 percent of Collateral consists of HD material, around 80 percent of the HD material was shot with Vipers, according to DP Dion Beebe, who took over for Paul Cameron four weeks into the shoot, after Cameron prepped the show with Mann, Canning, and associate producer Bryan Carroll.

When Viper took over as the project's lead acquisition tool, Collateral became the first big-budget studio feature film with a major star — Tom Cruise — to rely primarily on the Grass Valley Viper FilmStream camera system. It also became “a very complicated job,” says Canning, because of the mixed formats, the decision to utilize Vipers, and Mann's grueling creative quest for unique visuals to fit his story, which takes place during a dark and strange night in Los Angeles.

Mann was looking for “a new way of seeing Los Angeles at night — more the way you see it by eye,” says Cameron. “There is an atmosphere in the air, a glow around buildings and street lights, and other things you see that don't normally translate well on film. He wanted viewers to see into the night sky, as the horizon separates. That was very important.”

Figuring it Out

Mann achieved his look by capturing most of the movie in the Viper format — recorded to HDCAM-SR tape via Sony HDCAM SR-5000 decks — while capturing other images on film. Details came as the team improvised with and reconfigured elements of both the Viper and Sony cameras, devised unique lighting solutions, and went through a delicate digital intermediate with colorist Stefan Sonnenfeld at Company 3, Santa Monica, Calif., (see “Digital Intermediate,” p. 50).

It was not clear at the outset how — or even if — the look would be achieved. Early on, Mann's goals posed almost overwhelming preproduction challenges.

“We tested the Sony HDW-F900 and the F950, and we couldn't get the 950 to emulate the look we found in the 900,” Cameron recalls. “Then, we tested the Viper in FilmStream mode. The advantage there, of course, is that you are recording completely uncompressed, raw data, giving amazing resolution. The downside is that when you look at the photography on-set, you see a greenish-yellow raw scan on the HD monitor, and you have to output it to an RGB composite for viewing. That created a disadvantage — viewing a raw RGB image, you don't necessarily see what you are actually recording.

“Still, when we compared the same footage from film and the 900 and the Viper on a raw scan, we found the Viper rendered amazing color and detail. It gave us somewhere between the kind of elegant graininess of film when pushed, and the almost unacceptable noise you get when you push the 900 to plus-6 or plus-12 DB. So, it gave us an inherent noise value when you shot in dark situations that kind of emulated a film look more than an HD look on the filmout.

“We also had the issue with the Viper where the recording devices for using it handheld, running down the street, were limited. Bryan Carroll introduced us to a new recording device called an S.two D.Mag [portable digital recorder], which has the capability of holding five 30-minute hard drives for recording the raw data. That was our initial recording solution, but we ran into a few early glitches and that put up red flags. We were told we could use the S.two, but we'd have to back it all up onto a regular HD recording deck. That meant doubling up recording machines, and that was also a disadvantage. In the meantime, Plus-8 Video [Burbank, Calif.] worked with Bryan Carroll and our camera operators to begin reconfiguring the Viper camera, from the plates to matte boxes to follow focus, extenders, and safety switches. But unfortunately, that took us four weeks into the production by that point.

“Our problem was, do we engage with the Viper and accept its limitations in terms of viewing the images, plus the fact that, ergonomically, it was not really production ready at the time we started? Because of those issues, at first, we were pushed more toward using the 900. The notion was that the Sony would be the primary camera, and maybe we could do a few things with the Viper.”

The goal, however, remained to make Viper the primary camera. As the process of reconfiguring the Vipers continued, and principal photography got underway, Mann and his team considered using the Viper with modest compression, in a so-called VideoStream mode, capturing images as 10-bit, 4:4:4 RGB video, rather than data. This would allow filmmakers to take advantage of Viper's ability to automatically record in anamorphic, widescreen mode (2.37:1), rather than having to mask or crop the top and bottom of the images, and view those images on monitors during production, with less compression than other HD cameras.

“Since we were shooting off the bottom of color exposure values, it was crucial for Michael to be able to see and manipulate the images during production,” says Canning. “Therefore, we couldn't do this picture in FilmStream mode. But in VideoStream mode, Viper becomes a very high-end HD camera with acceptable compression, given our ability to compensate during the DI process. So, eventually, after starting with the 900 as our primary camera, we were able to make the switch to Viper as our primary camera, recording to HDCAM-SR tape using the Sony SR-5000 deck. By recording to HDCAM-SR, the highest value tape format available to us at the time, we could capture compressed images and have room to improve them later in post.”

Production

This approach gave filmmakers a workable production pipeline, allowing them to record both Viper and HDW-F900 material to HDCAM-SR, and Steadicam material via the HDW-F900 to on-board HDCAM tape. Those tapes then went to Laser Pacific, Hollywood, and were edited together into dailies, along with film sequences, after they were scanned to HDCAM-SR tape. The HDCAM-SR became the common platform for all formats for both viewing and finishing the movie. The dailies material eventually became the foundation of an HD master created at Company 3 to serve as a template for the final color-correction phase.

Around the time that the Viper ascended to primary status, Dion Beebe joined the production, replacing Cameron, who says only that he “got a wonderful R&D education” on the project.

When Beebe took over, he had a fast learning curve but credits Mann, Cameron, Canning, Plus-8 technicians, Laser Pacific, and Carroll for leaving him a workable production methodology. In particular, Canning “tweaked the matrixes in both the Viper and 900 cameras to pretty much match up what was recorded to tape,” Beebe says. Canning painstakingly matched the Sony camera's settings to the Viper's color settings in order to bring the cameras close together in terms of the tonality of colors they capture.

“Once I found out what Michael liked about the Viper after attending test color-correction sessions with him, I knew how to adjust the Sony camera to reproduce that color imagery closely,” Canning explains.

“If the Viper were further along ergonomically and had on-deck recording capability at the start, giving us some of the flexibility of the F900, we would have used it all the way through, except for the few daylight sequences, which were always targeted for film,” Beebe says. “But the reality was, we needed the F900 to fill some of the holes that were left at the outset. So, eventually, we came up with ways to figure out what scenes to allocate to which camera.”

The rules filmmakers came up with, according to Beebe, depended on what they were shooting.

“If we were in interior spaces, where we could control ambient light levels, we wanted to work with film,” says Beebe. “So sequences like the one in the Korean night club all went to film. The main thrust behind the HD cameras was night exteriors. That was where we could work with this incredibly light-sensitive Viper format and really see into the night in ways I had not seen before. When I came onto the project, we made Vipers the A and B cameras for most work, and then we carried the 900s with us throughout production, mainly for untethered, run-and-gun work.”

Viper's light-sensitive capabilities were particularly effective for extensive sequences shot inside the taxi driven by Jamie Foxx's character. A significant portion of the movie takes place in the cab, and Mann insisted on low light levels, while highlighting faces of the two characters.

“We discovered with close-ups, when the images of the actors' faces were seen on a big movie screen, we could see too much video noise at the lower light level that Michael preferred,” says Cameron. “During testing, we determined what levels would be acceptable, or not acceptable, in terms of lighting levels for close-ups. We created a correlating chart during the testing phase that told us what the keylight IRE should be at different exposures. At those levels, when looking on our HD monitors while shooting close-ups, the images looked extremely overlit. But we knew and accepted that, with the understanding that we could Power Window those shots during the DI.”

Cameron, gaffer Phil Walker, and Canning worked together to develop a customized method of lighting inside the cab that would serve this overall goal.

“In essence, we reinvented the wheel for lighting car interiors,” Cameron explains. “We created a lighting system using electroluminescent [EL] panels [created by Novatech of Simi Valley, Calif.]. Those are basically lights that look like laminated pieces of paper. Over a period of weeks during the testing phase, we cut and mixed phosphors for the paper panels to get the color temperature we wanted for the car interior. We then installed those lights with customized, low-voltage wiring and dimmer boxes for each picture car. This gave us the look Michael wanted — a kind of ominous lighting effect that makes it seem like there is almost no light on the actors. The goal was to keep the IRE level up to reduce the noise on the faces of the actors. For the most part, we shot at plus-6 DB on the Viper camera. Looking at the monitor, it seemed like we were 1 to 2 stops over what you would normally do in the film lighting world. But with our calculations, we knew how far we could go and still be able to Power Window those shots as needed.”

The filmmakers say viewing the Viper and HDW-F900 images on two Sony (BVM-F24 and D24) HD monitors clashed with the viewing needs of camera operators. The monitors' inability to show anamorphic, widescreen imagery required the crew to rely on Astro Systems' scan converters to create a widescreen image vertically on those monitors, giving Mann and his collaborators the view they required to make creative decisions. That approach, however, led to latency issues — essentially, a delay between the uncompressed image that operators could see on their viewfinder's LCD monitor and what they were taping.

“Because we were capturing an anamorphic signal, we had to collapse a vertical scan on the CRT monitor to see the correct aspect ratio,” explains Canning. “But the LCD monitor on the cameras, for local monitoring, won't let you do that. We needed the Astro scan converters on the output to make a scan we could see, but this, in turn, caused the latency problem.”

“That lag in the viewfinder was difficult for our operators,” adds Beebe. “For me, as the DP, the little black-and-white viewfinder was not much help anyway. The monitor became what I relied on, and that meant the digital imaging technician [Canning] was crucial. He did a great job calibrating and matching the monitors precisely.”

There were also related audio delays on-set during playback of sequences, since the scan converter's playback was delayed and not in synch with the audio playback. “There is no question that latency issues with images and sound are a problem when doing video production at this level,” adds Canning. “There are ways around some of it, and you can live with much of it, so our guys just dealt with it. But it is a major issue.”

Plus-8 technicians, in collaboration the project's camera team, Canning, and Mann himself “did a nice job reworking these cameras” to solve ergonomic issues that made the cameras difficult to use when production started, says Beebe. “We put counterweights on the back of the cameras, built brackets at the end of the camera to balance it out, all sorts of things to make the Vipers more accessible. Things got easier and more efficient as the production progressed.”

---

Sidebar

Digital Intermediate

By the time Collateral's production officially moved to Company 3, Santa Monica, Calif., for the DI phase, colorist Stefan Sonnenfeld — a longtime Michael Mann collaborator — had already been deeply immersed in the project for some time. Sonnenfeld visited the set with Mann early in the shoot, conducted repeated tests to help finalize the look, and working with Laser Pacific, helped build a rough HD version of the movie.

“Michael involved me far earlier than I usually get involved on a feature film,” says Sonnenfeld. “We did so many back-to-film tests early on, since Michael is such an organized guy who explores all possibilities before he makes decisions. Involving me early as the colorist was part of that exploration.”

Company 3 scanned film segments on its Spirit telecine at 2K, and put that material, along with selected HDCAM-SR and HDCAM material into its SAN (built by Bright Systems, Reno, Nev.), permitting Quantel iQ editor Rob Doolittle to conform the piece. Company 3 had about 50TB of total storage at its disposal during the project, including about 20TB of SATA arrays, 8TB of fiber channel drive storage, and another 20TB from the high-performance Dylan storage drives attached to the iQ system. Sonnenfeld then color corrected the movie on his Da Vinci 2K. Eventually, the entire piece was recorded out to film at EFilm, Hollywood, on Arri laser recorders.

“Basically, we did the HD preview first — taking those tapes from Laser Pacific and doing conforms as they were editing, starting to finalize stuff,” says Sonnenfeld. “I did a pre-color-correction run through with Michael Mann for that HD preview, and that got us close to where Michael was comfortable. We used the HD preview as the basis for our color correction, and then, in the final color correction, we kept doing tweaks and changes based on how Michael felt the movie looked on a big screen.”

Sonnenfeld says his biggest creative challenges involved subtle differences between the images coming from different formats, emphasizing and highlighting the night lighting, and tweaking light values for close-up scenes.

“In terms of the night, that was complicated,” Sonnenfeld explains. “Michael's point was that when you look outside in the city at night, you don't just see black skies with contrasty light. You see a brighter sky, with weird sodium, mauve, and magenta colors in the sky, along with wild flares and halos and mid-range tonal ranges. Some filmmakers make that dark and contrasty, but it really isn't. Michael asked me to highlight this point in the DI. He captured the basic look digitally because it is not something you can do on film, and then I had to tweak it. They had to push the footage in-camera to amplify the signal using the DB gains on the HD cameras. So my challenge was to make sure things did not look overdone or overamplified.

“As to the light values on the faces inside the cab, that is a good example. They had to overlight stuff to get more exposure. You could not adjust that in a photochemical environment. So I had to do it with Power Windows. Some shots ended up with 12 Power Windows on them — places where I isolated those different bright areas and took them down. It was a very specific color correction process.”

DP Dion Beebe adds that the plan for manipulating light on actors' faces during close-ups perfectly exemplifies how, in high-end digital cinematography, you have to do things specifically designed toward the post process.

“The way we were working, in the cab, we just calculated that the light levels on faces needed to be up, and that we had to have values of 20 to 30 percent, irrespective of whatever the background levels were,” says Beebe. “We knew, and planned for, what would be done in post with Power Windows to isolate faces and bring them back down to levels that matched the exteriors. In our case, this shows that Viper and HDCAM-SR were not magical, quick fixes, but they are viable formats to fit particular aesthetic choices made by particular filmmakers.”
— MG

© 2008 Penton Media, Inc.