Digital intermediate

Digital intermediate (typically abbreviated to DI) is a motion picture finishing process which classically involves digitizing a motion picture and manipulating the color and other image characteristics. It often replaces or augments the photochemical timing process and is usually the final creative adjustment to a movie before distribution in theaters. It is distinguished from the telecine process in which film is scanned and color is manipulated early in the process to facilitate editing. However the lines between telecine and DI are continually blurred and are often executed on the same hardware by colorists of the same background. These two steps are typically part of the overall color management process in a motion picture at different points in time. A digital intermediate is also customarily done at higher resolution and with greater color fidelity than telecine transfers.

Although originally used to describe a process that started with film scanning and ended with film recording, digital intermediate is also used to describe color grading and final mastering even when a digital camera is used as the image source and/or when the final movie is not output to film. This is due to recent advances in digital cinematography and digital projection technologies that strive to match film origination and film projection.

In traditional photochemical film finishing, an intermediate is produced by exposing film to the original camera negative. The intermediate is then used to mass-produce the films that get distributed to theaters. Color grading is done by varying the amount of red, green, and blue light used to expose the intermediate. This seeks to be able to replace or augment the photochemical approach to creating this intermediate.

The digital intermediate process uses digital tools to color grade, which allows for much finer control of individual colors and areas of the image, and allows for the adjustment of image structure (grain, sharpness, etc.). The intermediate for film reproduction can then be produced by means of a film recorder. The physical intermediate film that is a result of the recording process is sometimes also called a digital intermediate, and is usually recorded to internegative (IN) stock, which is inherently finer-grain than camera negative (OCN).

One of the key technical achievements that makes the DI possible is the look-up table (aka "LUT"), which can be made to mimic how the digital image will look, once it's printed onto normal release print stock. DI facilities generally allow comparing the digital image directly to a print on the same screen, ensuring precise calibration of the process.

The digital master, created during the Digital Intermediate process, can be recorded to very stable yellow-cyan-magenta (YCM) separations on black-and-white film with an expected 100-year or longer life.

The digital master is often used as a source for a DCI compliant distribution of the motion picture, for digital projection as well.

History

Telecine tools to electronically capture film images are nearly as old as broadcast television, but the resulting images were widely considered unsuitable for exposing back onto film for theatrical distribution. Film scanners and recorders with quality sufficient to produce images that could be inter-cut with regular film began appearing in the 1970s, with significant improvements in the late 1980s and early 1990s. During this time, digitally processing an entire feature-length film was impractical because the scanners and recorders were extremely slow and the image files were too large compared to computing power available. Instead, individual shots or short sequences were processed for special visual effects. In 1992, Visual Effects Supervisor/Producer Chris F. Woods broke through several "techno-barriers" in creating a digital studio to produce the visual effects for the 1993 release Super Mario Bros. It was the first feature film project to digitally scan a large number of VFX plates (over 700) at 2K resolution. It was also the first film scanned and recorded at Kodak's just launched Cinesite facility in Hollywood. This project based studio was the first feature film to use Discreet Logic's (now Autodesk) Flame and Inferno systems, which enjoyed early dominance as high resolution / high performance digital compositing systems. Digital Film compositing for Visual Effects was immediately embraced, while optical printer use for VFX declined just as quickly, and never came back. Chris Watts further revolutionized the process on the 1998 feature film Pleasantville, becoming the first visual effects supervisor for New Line Cinema to scan, process, and record the majority of a feature length, live-action, Hollywood film digitally. The first Hollywood film to utilize a digital intermediate process from beginning to end was O Brother, Where Art Thou? in 2000 and in Europe it was Chicken Run released that same year.

The process rapidly caught on in the mid-2000s. Around 50% of Hollywood films went through a digital intermediate in 2005, increasing to around 70% by mid-2007.^[1] This is due not only to the extra creative options the process affords film makers but also the need for high-quality scanning and color adjustments to produce movies for digital cinema.

Milestones

• 1990 – The Rescuers Down Under – First feature-length film to be entirely recorded to film from digital files; in this case animation assembled on computers using Walt Disney Feature Animation and Pixar's CAPS system.

• 1993 – Snow White and the Seven Dwarfs – First film to be entirely scanned to digital files, manipulated, and recorded back to film. The restoration project was done entirely at 4K resolution and 10-bit color depth using the new Cineon system to digitally remove dirt and scratches and restore faded colors.^[2]

• 1998 – Pleasantville – The first time the majority of a new feature film was scanned, processed, and recorded digitally. The black-and-white meets color world portrayed in the movie was filmed entirely in color and selectively desaturated and contrast adjusted digitally. The work was done in Los Angeles by Cinesite utilizing a Spirit DataCine for scanning at 2K resolution^[3]

• 2000 – O Brother, Where Art Thou? – The first time a digital intermediate was used on the entirety of a first-run Hollywood film which otherwise had very few visual effects. The work was done in Los Angeles by Cinesite utilizing a Spirit DataCine for scanning at 2K resolution, a Pandora MegaDef to adjust the color and a Kodak Lightning II recorder to output to film.^[4]

– Chicken Run was the first feature film in Europe to use the Digital Intermediate process, digitally storing and manipulating every frame of the film before recording back to film.

• 2004 – Spider-Man 2 – The first digital intermediate on a new Hollywood film to be done entirely at 4K resolution. Although scanning, recording, and color-correction was done at 4K by EFilm, most of the visual effects were created at 2K and were upscaled to 4K.

• 2008 – Baraka – The first 8K resolution digital intermediate by FotoKem of a 65 mm negative source for the October 2008 remastered DVD and Blu-ray Disc release, as well as for producing new 70 mm prints. The scan produced 30 terabytes of data and took 12–13 seconds to scan each frame, for a total scan time of over 3 weeks.^[5]

See also

• Color grading
• Telecine

References

1. ^ Belton, John (Spring 2008). "Painting by the Numbers: The Digital Intermediate". Film Quarterly 61 (3): 58–65. doi:10.1525/fq.2008.61.3.58. 
2. ^ Holusha, John (June 30, 1993). "'Snow White' is made over frame by frame and byte by byte". New York Times. pp. 5. 
3. ^ Bob Fisher (November 1998). "Black & white in color". American Cinematographer. http://www.theasc.com/protect/nov98/pleasantville/. 
4. ^ Bob Fisher (October 2000). "Escaping from chains". American Cinematographer. http://www.theasc.com/magazine/oct00/brother/. 
5. ^ Andrew Oran (2008). Baraka: "Restoration" feature documentary (DVD/Blu-ray). Magidson Films, Inc. 

External links

• The Digital Intermediate Guides – DI Guide, & Scene-to-Screen – Light Illusion, DI Consultancy.
• DI Guide – A Digital Intermediate Guide – By Phil Green, DI Specialist & Colourist.
• Digital Intermediates For Film and Video – a book on the subject.
• Color grading on King Kong – Video about color grading done on KingKong.
• "Data or Video" article about data vs video for color grading