A high-speed interface between the Quantel iQ and Cintel's DSX, C-Reality and Rascal film scanners was recently announced, which means that the iQ can now be controlled by Cintel, boosting productivity in a virtual grading environment. In another twist on the DI pipeline, iO Film uses the Avid DS HD as a controller for the Spirit.

Despite the availability of third-party software and hardware solutions, the proprietary color-grading solution is far from dead. EFilm, for one, continues to rely on proprietary technologies for dust-busting, repair and color-timing. "By continuing to develop our own gear, we can implement something new quickly when a client needs it," notes Matza. "If you buy an off-the-shelf system - which I'm not against - then you have to wait for the manufacturer to come up with the next revision. We have the flexibility and power to develop and provide what clients need."

In terms of recording digital files back out to film, there are currently two choices: Arriflex's Arrilaser recorder and Celco's Fury Film Recorder. (Several Kodak Lighting Recorders are also in the field, but they are no longer manufactured.) Based on solid-state lasers, the Arrilaser 2K offers recording at 3.2 seconds per frame (at 2K resolution); the Arrilaser Performance offers 3.2 seconds for all formats up to 2K, and 4.9 seconds for 4K. The Celco Fury is notable for its speed - an output of 1 frame per second for both HD and 2K images onto Kodak 5245, and less than two seconds per frame for a full Cineon density range 2K image onto Kodak 2242. The system is also capable of high-speed output of any resolution up to 4K for large formats, such as 70mm.

Storage is another consideration for facilities planning to offer the DI process. Digital images are storage-hungry, and storage is expensive. EFilm, for example, has 60 TB of storage with a combination of SGI, LSI and other systems. At Modern Video Film, which relies on the iQ for the middle portion of the DI process, storage is 12 TB, all on Quantel Dylans for online storage. "We're working on the problem of near-line storage, for when you need to move a project that you're not finished with, as we speak," admits Modern Video Film's Barkat, who adds that the facility uses Bright Systems asset-management software  "The ability to just dump something to tape and put it on the shelf isn't practical with the amount of data we have."

Another limiting factor is the speed at which the data moves around. Practical networks only move the 2K frames around at perhaps 3 frames per second, and even the fastest network has trouble keeping up with 300 megabytes per second. Storage area networks (SANs) are a popular solution for moving data from servers to workstations. Cinesite has one based on Blue Arc and Sands storage devices, and Éclair Labs has implemented a SAN with an SGI Origin 200 file server running CXFS (Clustered Extended File System).

Managing data is another trick. "Managing that much data is very, very hard," admits Technique's Mavromates, who also supervised the DI on Panic Room (AC March '02). Peter Doyle, supervising digital colorist on The Lord of the Rings, says his team at The Post House built a database that could track color grades, so that whenever someone called up a shot, he knew what grade the shot had. "Our production and administration teams could access all the same data," says Doyle. "As a virtual private network, we could also access it from outside. When I'm in the lab at Deluxe, I can go into the database and see how a grade is looking."

Monitoring may be the weakest link in the digital-grading pipeline. Ensuring that what is seen on the monitor or screen is identical to what the image will look like when it's recorded out to film is crucial to the process. Though many would argue that it's impossible to match an electronic signal to celluloid, many facilities have gone to great lengths to ensure the closest possible match. For feature-film resolution, everyone agrees that a projected image - rather than the HD monitors found in the HD telecine suite - is the way to go. For that reason, the screening room is becoming de rigueur at DI facilities. "It's very difficult to get what you see on the monitor to look like what you'll output to film, and there are now some beautiful projectors that were designed with this process in mind," notes Ritchie.

For The Lord of the Rings, The Post House utilized the prototype Colossus to mimic the lab style of grading as closely as possible, so cinematographer Andrew Lesnie, ACS could ask for - and get - three points of cyan, for example. Lesnie says he got what he wanted, but he warns of the pitfalls in the DI process. "What you have is enough tools to alter all of the characteristics of film stock in a huge way," he cautions. "It's important to establish parameters that keep you on the straight and narrow, because it's very easy to lose your place. We weren't grading a 30-second commercial; we were grading sequences that had to fit into the rest of the film."

Poster, who digitally graded Stuart Little 2 at Sony Imageworks, stresses that for an effects-laden film, it's imperative that the visual-effects scans be timed by the cinematographer before they go to the compositer. "Normally the visual-effects artists grade the shot themselves and the compositor works on it," he says. "But to have a completely smooth timing event, the scan should be timed by the cinematographer before it goes to the compositor so it will match the eventual digital grade."

Facilities offering DI services hope that digital mastering will eventually be incorporated into the production workflow as an integral part of creating the desired look of the film. If and when that happens, says Ritchie, "it could have a dramatic impact on the way we make movies - and give filmmakers a fantastic suite of tools to play with."