by Rainer Standke
In the last year or two, the price of scanning film and recording it back to celluloid has come down so much that it is now economically feasible to bring an entire show into the digital
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Scanning and film recording require a clean environment and plenty of gear. Brian Nogle works in Pacific Title's digital scanning and laser film recording room with their Kodak Genesis scanners and Lightning film recorders. |
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Creative Benefits
What does the digital intermediate process offer? Most important, it provides unprecedented control over film color. Once your show is digitized, all the sophisticated color correction tools that are standard in video become available for film. Dark, medium and bright parts of an image can be timed separately, contrast can be adjusted, color can change gradually within a shot, "power windows" can alter specified areas within the frame, and secondary color correction, where each color can be tweaked individually, is available. All of this happens in real-time, and with random access to the entire show.
This degree of control is available for entire features, allowing the creation of a look that would otherwise be impossible or require relatively unpredictable custom processing. One of the first films to use digital intermediate for stylistic purposes was O Brother, Where Art Thou? by the Coen brothers. The desaturated, tinted look was achieved at Cinesite.
Another major advantage digital intermediate offers is that color correction is done only once, and the resulting file is then used to produce film and all video versions. Directors, cinematographers and editors can control and approve in one place the timing of all versions of their show and take care of other tasks, such as pan and scan and letterboxing, at the same time.
Not only can a show be color corrected in ways not previously possible, but the fact that the entire show will be manipulated digitally extends the creative palette and gives production the freedom to use more visual effects. As a result, it might allow some shows to shoot faster and, for better or worse, with less discipline. For example, a period piece could shoot with modern airplanes or TV aerials visible, knowing that they could easily be removed later. Digital intermediate also provides an elegant way to combine footage shot in different formats, be it film or video.
The process isn't free -- traditional lab work is still cheaper for film delivery alone, and it takes more time than traditional film timing. But digital intermediate combines many processes and many budget items. The combined line items for film and video timing, titles and bread-and-butter opticals (fades and dissolves) can typically pay for a full digital finish. And prices will inevitably come down.
Scan Sizes
Scanning film takes time, and time is money. The result is that filmmakers and vendors must make choices about how much data is scanned from each frame. This number, the scan resolution, influences the economics of the entire process. Scans are measured in thousands of pixels of horizontal resolution. One "K" means 1,024 pixels. A full-aperture "4K" scan has 4,096 pixels horizontally, and 3,112 pixels vertically. 4K is the current gold standard, and it's
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How do these resolutions compare to film? Theoretically, based on the grain structure of the emulsion, film could be pegged as high as 6K. Practically, however, this is only true for first-generation camera original and only under ideal conditions. In practice, negative film is typically assumed to have a maximum resolution of about 4K. Release prints from an internegative, depending who you talk to, are said to have a resolution of well under 1,800 pixels across, and the projected image may actually be worse because lamps can be misaligned, and lenses can be dirty or out of focus.
4K and 2K scans can be made in film scanners, which are dedicated devices with traditional pin registration. This is a relatively slow process: one frame every 3 to 12 seconds. Scanning a 100-minute feature this way can take more than a week of round-the-clock scanning. That's why some houses are using devices based on high-definition telecine technology. The most common is the Spirit DataCine, made by Thomson Multimedia, which bought the technology from Philips. They scan much faster, at about six frames per second, which brings down the time to scan a 100-minute show to a much more reasonable seven hours or so. This kind of speed helps make the digital intermediate process affordable.
The DataCine makes scans at 1,920 x 1,440, which is just under true 2K. To fill the standard 2K frame, these scans have to be up-sampled, which entails the risk of degrading image quality. What's more, the DataCine samples color more coarsely than a conventional scanner. Theoretically, this means that DataCines make slightly inferior scans, but the difference can be subtle, and their cost advantages make them appealing in many environments.
What is the right scan size for digital intermediate? Purists say that 4K is the only way to go. But many people say that 2K is more than good enough for theatrical distribution, since it offers as much or more resolution than the film prints we're seeing now. By the time you read this, three new digital intermediate shows should be in theatrical release: We Were Soldiers, scanned at true 2K by Efilm, and two films transferred on DataCines: Hart's War out of Cinesite, and Panic Room done at Technicolor's digital facility, Technique.
Workflow Choices
The simplest digital intermediate process entails scanning a cut negative. The resulting file can be color corrected, titles can be added, and some effects work can be done. This is the process that has been used most often so far. It's straightforward and relatively economical. But it's tantalizing to consider the possibility of scanning uncut negative. This would theoretically allow a show to be recut in the workstation, without the limits that negative splices now put
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Director of photography Alar Kivilo, C.S.C., and colorist Jill |
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Supervising digital colorist Peter Doyle and first assistant editor Peter Skarratt put together a unique digital intermediate workflow for The Lord of the Rings. As soon as the editor and director had a cut of a scene with a certain degree of finaity to it, negative was pulled and assembled flash-to-flash, and the sections used were scanned with handles. Copies of the resulting files were converted to low-resolution QuickTime movies, which were then imported into the Avid and cut into the show, replacing the original dailies. An EDL was made for conforming the 2K files, so that preliminary timing and effects work could begin -- before a scene was locked. Preliminary outputs to negative were made as well, so that lab timing could start. This workflow effectively provided something like a non-linear online process that allowed for picture changes much later than a reel-by-reel process would. Eventually, the entire show, with its roughly 3,500 cuts, had 600 negative splices in it.
At present, digital assembly presents some thorny issues of data management because scans don't contain key number information. There's also no standard format for machine-readable cut lists -- no list that the Avid can create to help assemble the show automatically. That means that there can be plenty of confusion when it comes time to put a show together. A new file format for scans is on the horizon that will accommodate more "meta data" (including key numbers) in the scan file itself. But for the moment, scanning is largely done with start marks and frame counts.
Once the show is scanned and visual effects are incorporated, color correction can be done with several systems. Digital timing offers capabilities that film professionals have only dreamed about in the past, allowing the look of a show to be refined in ways that were formerly impossible by any means. According to Bruce Everett, co-producer of HBO's mini-series Band of Brothers, the stylized colors of the show were created entirely in post. After desaturating, "squashing" and tinting the image, secondary color correction was used to get skin tones, muzzle flashes, etc. back to a more natural look. The process also included some digital assembly: Negative was cut with handles and then built in a Philips Specter Virtual Telecine. This allowed some material to be reused without making dupes and kept the film cleaner. Scanning was done with a DataCine at Cinesite in London. The full negative was recorded, which allowed 4:3 versions to be made by opening up the top and bottom of the frame, rather than by cropping the Super 35 image.
Alar Kivilo, who shot Hart's War, says that while changes can be made with great speed in the digital suite, it's easy to get carried away and spend too much time creating too many variations. To avoid doing so, he recommends being very clear about the look before starting, then sticking to that decision. He also warns that while there's a great temptation to use the
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One critical issue for color correction is fidelity from the timing environment to the final film print. Monitoring can be done on specially calibrated high-definition video projectors or on CRTs. The goal is to pre-visualize the final film look as accurately as possible, and no system is perfect. It is this area of color fidelity that has seen some major hiccups in the past. Cinematographer Conrad W. Hall, who used the digital intermediate process for Panic Room, says that the colors and brightness of the projected image changed during the six weeks that he spent in color correction. But he adds that this and other bugs will be worked out as more people use the process and the technology matures. In his view, the creative freedom afforded by digital intermediate was more than worth the trouble and time involved.
Kivilo found that one big hurdle was making the correlation between the image on the video screen and the one that ultimately appeared on film. At the end of each day's digital session for Hart's War, he saw only a few short test shots on film, rather than an entire reel, as he would have in the traditional process. This made it even more critical to understand the way the look on the monitor translates to film. In some instances, Kivilo learned to compensate for certain discrepancies -- to make amber colors vibrant on film, for example, he found he needed to push them in the digital suite, until they looked almost too electric to the eye.
Once a show is color-corrected, it must be recorded out to film. Outputs can be made to interpositive, from which internegatives are made in a traditional lab process, or each printing negative can be output individually. That's more expensive, but it produces better quality -- every print is generationally closer to the original negative. Super 35 shows will also confront the question of where to do their squeeze: either digitally or conventionally. FotoKem's Chapman says that at the moment, recording technology lags behind that of scanning, so it is a much slower process: Recording takes about three to five seconds per frame, which means that each machine can record roughly 1,000 feet per day.
In some cases, digital intermediate can even make sense without a film release. Cynthia Kanner, HBO Films vice president of post-production, points out that there is currently no way to tell what the life span of videotape will be. Film is still the most reliable form of long-term storage, so even if a show were assembled digitally, HBO would still cut negative for archival purposes. HBO Films started using digital intermediate three years ago, and on each
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Digital imaging technician Steve Hodge at work in Technique's scan-record room. To his right is an Arrilaser film recorder and in the background is a Spirit DataCine. Photo by Tony Friedkin, SMPSP, courtesy of Technique. |
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Facilities
Digital intermediate is a new business that's becoming attractive for existing film and video houses, because it combines many services they already sell with new tasks that are just now becoming economically viable. It concentrates in one place the finishing work that used to be spread out over several facilities, and it uses much of the equipment and expertise that some companies already have in-house. Several vendors on the West Coast now offer digital intermediate services and more will follow in the future.
Pacific Title, known to many Guild members for its traditional optical services, has invested heavily in digital effects equipment and now has a full digital department and a high-quality scanning and film recording facility. They are the only vendor outside of Kodak's Cinesite that has Cineon scanners and film recorders. The Cineon hardware was designed by Kodak to make digitally treated film look good enough to seamlessly intercut with original negative. Pacific Titles's president Phil Finer stresses the quality of the scans that their equipment produces and points out that only full 4K scans can produce an archival representation of everything on the film. The company has been doing digital intermediate work for trailers, timing with Discreet Infernos using CRT monitors calibrated to the film output. Finer is putting in the infrastructure to do entire features and intends to make the service available in the next few months.
Technique is the new digital branch of Technicolor, in operation only since last December. Their first digital intermediate projects are Coastlines, directed by Victor Nuñez and shot on Super 16, and Panic Room, directed by David Fincher. Technique uses a Spirit DataCine for scanning, Pandora MegaDEF and DaVinci 2K equipment for timing and Arrilaser recorders for outputs. Executive vice president Peter Sternlicht thinks that 2K is sufficient for current theatrical distribution, but expects to migrate the digital intermediate process into the realm of 4K within 12 to 18 months. Peter Mavromates, post supervisor on Panic Room, said that due to Technique's rigorous calibration work, the film outputs he has seen were extremely close to the projected video that was used for timing.
In addition to their reputation as an effects house, Cinesite has a long history in scanning and recording back to film. The company did early work on O Brother, Where Art Thou?, digital color correction for Pleasantville and also created the first digital Super 16 blow up for Urbania. Cinesite uses both Cineon scanners and DataCines. According to Randy Starr, vice president of business development, the choice between the two is made on a per project basis, depending on the budget and the degree of manipulation needed. Some comparison testing is usually done before the actual work begins. If a show needs only timing and basic effects like dissolves and titles, the more economical DataCine is usually chosen. Starr envisions a streamlined workflow in the future in which editing, dirt cleanup, timing, visual effects and trailers are all worked on concurrently, using same scanned data.
Efilm is known for its transfers from video to film, as well as film scanning and recording work. Imagica XE scanners from Japan are used for true 2K and 4K scans. On the feature We Were Soldiers, the negative was "overscanned" at 4K, and the resulting data was then down-sampled to 2K, yielding a crisper image than a straight 2K scan, but making it possible to work more quickly and efficiently. Seasoned film timer Mike Stanwick, on loan from Deluxe, was brought in to help with the digital timing. Efilm's proprietary timing and conforming software is resolution-independent, and allows 2K and 4K scans to be mixed in the same reel, a feature that's useful for things like resizes and push-ins. In an effort to eliminate lab timing entirely, Efilm's Arrilaser film recorders are recalibrated constantly to compensate for chemistry fluctuations and the high definition video projector used in timing has settings that closely emulate each film emulsion used. According to Efilm's president, Joe Matza, We Were Soldiers is the first film to have been fully mastered at true 2K resolution, timed entirely on a computer and released with no lab timing. Editor William Hoy was very satisfied with the process and indicated that digital intermediate gave the team creative possibilities that they couldn't have had otherwise.
Many other facilities, including FotoKem, DuArt and Command Post/Toybox are now offering the service or expect to be doing so shortly. Laser Pacific, building on their extensive experience with high-definition video, plans to offer digital intermediate services for features starting some time in the first half of 2002.
The Future
Digital intermediate technology is evolving quickly, and prices are expected to come down as new and faster equipment becomes available. Thomson is currently developing the Spirit DataCine 2, to be released in October. It is said to make true 2K scans in 14-bit RGB at a rate of 30 frames per second, as well as 4K scans at 6 to 8 fps. Other high-speed, high-resolution scanners are in the works from Sony, Cintel, ITK and others. In addition, Kodak is developing a digital projector that will be capable of showing true 2K images -- at about half the cost of today's digital projectors with pixel dimensions of only 1,280 x 1,080. This may create a de facto standard of 2K for digital cinema theatrical distribution. The digital intermediate process should fit into that nicely.
In an environment where video acquisition is starting to make inroads in feature production, digital intermediate offers a new lease on life for celluloid, giving filmmakers many of the creative tools that their TV counterparts have used for years. At the same time, the process takes us one step closer to a full digital workflow where all circled takes are scanned and a cut show is built entirely in the digital domain. Though we're not quite there yet, as prices come down, some type of digital intermediate process may soon seem like a creative no-brainer for any show that will be released on film.
Copyright © 2002, All Rights Reserved, The Motion Picture Editors Guild, IATSE Local 700