FotoKem worked to keep Christopher Nolan’s 65mm source natively photochemical and to provide the truest-to-film digital cinema version possible
By Adrian Pennington
Tipped for Oscar glory, Christopher Nolan’s intense World War II masterpiece, Dunkirk, has pushed the boundaries further than any film before it. Having shot sequences of his previous films (including Interstellar) on IMAX, this time the director made the entire picture on 65mm negative. Approximately 75% of the film was captured on 65mm/15-perf IMAX (1.43:1) and the rest on 65mm/5-perf (2.2:1) on Panavision cameras.
Nolan’s vision and passion for the true film experience was carried out by Burbank-based FotoKem in what became the facility’s biggest and most complex large format project to date. In addition to the array of services that went into creating two 65mm master negatives and 70mm release prints in both 15p and 5p formats, FotoKem also provided the movie’s DCP deliverables based on in-house color science designed to match the film master. With the unique capability to project 70mm film (on a Century JJ projector) side by side with the digital projection of 65mm scans, FotoKem meticulously replicated the organic film look shot by Hoyte van Hoytema, ASC, NSC, FSF, and envisioned by Nolan.
In describing the large format film process, Andrew Oran, FotoKem’s VP of large format services, explains, “Hoyte was in contact with FotoKem’s Dan Muscarella (the movie’s color timer) throughout production, providing feedback on the 70mm contact and 35mm reduction dailies being screened on location. The pipeline was devised so that the IMAX (65mm/15p) footage was timed on a customized 65mm Colormaster by FotoKem color timer Kristen Zimmermann, under Muscarella’s supervision. Her timing lights were provided to IMAX Post, who used those for producing 35mm reduction prints. Those prints were screened in Los Angeles by IMAX, Muscarella and editorial, who in turn provided feedback to production on location. Prints and files travelled securely back and forth between FotoKem and IMAX throughout each day by in-house delivery personnel and via FotoKem’s proprietary globalDATA e-delivery platform.”
A similar route was taken for the Panavision (65mm/5p) footage — also under Muscarella’s keen eye — prior to FotoKem producing 70mm/5p contact daily prints. A set of both prints (35mm and 70mm) were transported for screening in a trailer on location 50,000 miles away in England, France (including shooting on Dunkirk beach itself) and The Netherlands. Traveling with editorial during principal photography was a 70mm projector on which editor Lee Smith, ACE, and Nolan could view dailies in 70mm/5 perf. A 35mm Arri LocPro was also used to watch reduction prints on location.
Oran adds, “Zimmermann also applied color timing lights to the 65mm/5p negatives for contact printing to 70mm at FotoKem. Ultimately, prints from every reel of film negative in both formats were screened by Dan at FotoKem before shipping to production. This way, Dan ensured that the color was as Nolan and Hoytema envisioned. Later, the goal for the DCP was to give the audience the same feel as if they were watching the film version.”
HD deliverables for editorial and studio viewing were created on a customized Millennium telecine. Warner Bros. and Nolan required the quality be high at this step of the process — which can be challenging for 65mm formats. To do this, FotoKem made improvements to the 65mm Millennium telecine machine’s optical and light path, and fed the scans through a custom keycode and metadata workflow in the company’s nextLAB media management platform. Scans for the film’s digital cinema mastering were done at 8K on FotoKem’s Imagica 65mm scanners.
Then, to produce the DCPs, FotoKem’s principal color scientist, Joseph Slomka, says, “We created color modeling tools using the negative, interpositive and print process to match the digital image to the film as precisely as technically possible. We sat down with film prints and verified that the modeling data matched a printed original negative in our DI suite with side by side projection.”
This is where FotoKem colorist Walter Volpatto says he determined “how much” and “how close” to match the colors. “We did this by using a special machine — called a Harrahscope Minimax Comparator Projector, developed by Mark Harrah and on loan from the Walt Disney Studios — to project still IMAX frames on the screen,” Volpatto elaborates. “We did this for 400 images from the movie and looked at single frames of digital (projected from a Barco 4K DLP) versus film from Harrahscope, and compared, using the data created by the modeling tools.”
Volpatto worked mainly with RGB offsets in Resolve after each single frame verification to maintain a similarity to traditional color timing. “We also modified the DLP white point settings of the projector for purposes of maintaining the closest match,” he says. “Then, once all the tweaks were made with the stills, we moved to motion picture film reels. Everything described in the printer lights at the film stage were translated to digital based on modeling data.”
In addition to working with Dan (Muscarella) on the film screenings to see the quality he would need to match, Volpatto says that working on Interstellar also helped inform him how to approach this process. “It’s about getting the look that Nolan wants — I just had to replicate it with tremendous accuracy on Dunkirk.”
Aside from the standard DCP, two further digital masters were created for distribution including IMAX scans and digital IMAX distribution, and a Dolby Digital Cinema HDR Master from same source material.
“For the Dolby pass, we had to create another set of color science tools — that still represented Nolan’s vision — to exactly replicate the look of film to HDR,” says Slomka. “Because we had all the computer modeling tools used earlier in the process to identify how the film behaved, we were able to build on that for the HDR version.”
Adds Volpatto, “The whole pipeline was designed to preserve the original viewing experience of print film – everything had to integrate purely and unnoticeably. Having this film and color science knowledge here at FotoKem, it’s hard to see that anybody else could achieve what we did at this level.”