Time Warp
Karen Moltenbrey
May 16, 2019

Time Warp

It’s funny how the effects of time can have a profound effect on perspective. And, in a number of ways. Consider the groundbreaking documentary  They Shall Not Grow Old , for which aged, scratched, jumpy footage from World War I was restored to pristine condition and retimed to run smoothly. In doing so, it brings the hazy past into the present, and brings the reality of the subjects – often lost due to the condition of the old film – into sharp focus.

Directed by acclaimed filmmaker Peter Jackson, the production utilizes state-of-the-art post-production techniques and technologies, turning damaged early-1900s hand-cranked black-and-white film with no sound into pristine, authentically colored sequences paired with actual sounds and voice recordings from those who lived the experience. What’s more, the film was presented in stereo 3D.

“When it all came together, what really hits you is the humanity of the people in the film. They just jump out at you, especially the faces,” says Jackson. “They’re no longer buried in a fog of film grain and scratches, and shuttering and sped-up footage. You understand that these were human beings.”

History Comes to Life

The film was co-commissioned by 14-18 NOW WWI Centenary Art Commission and the British Imperial War Museum in association with the BBC. Four years ago, the Imperial War Museum approached Jackson about making a documentary on any aspect of the First World War for the 100-year celebration of the WWI armistice, but there were caveats: that he use their original archival footage, and that he use it in a fresh, original way. Jackson decided on a documentary that captures the shared experience of the British infantry soldiers at the Western Front, albeit with 100-year-old footage restored to present-day standards using today’s computer technology.

To ensure this was even possible, Jackson and the crew at his New Zealand-based Park Road Post Production spent a few months devising a restoration pipeline for the black-and-white footage in the film, as did Burbank, CA-based Stereo D for the colorized portion that turned back the clock, so to speak. Park Road began working with scanned raw footage, completing an initial contrast level pass and a grain reduction, to give it consistency before it could be colorized,” says Matthew Wear, Park Road colorist.

Making this even more challenging was the fact they were not working with all originals, but with duplicates, and even duplicates of duplicates. Moreover, the footage had been filmed on hand-cranked cameras, where the original speeds were fast but unknown. So Park Road began the arduous task of solving that problem so the footage later could be retimed to run at a more natural 24 fps – a process that required a lot of trial and error. The results determined that the actual crank speed had ranged from 10 fps to 18 fps depending on the cameras and operators. 

For the black-and-white shots, the Park Road team had to devise a method for eliminating artifacts that resulted from the retiming process. “The grain and scratches were easy to fix, it’s really just paint work and a lot of hours. The bigger problem was in the retiming. When you have film running at 13 or 14 fps, you have to make up extra frames to get to 24 fps, and in doing that, you’ll get artifacts,” says Ian Bidgood, director of engineering – picture. It was an issue Stereo D had to address for the material being colorized as well.

Once Park Road unlocked the speed conversion ratio formula, they provided that vital information to Stereo D, which was tasked with restoring and retiming, then colorizing, between 300 and 350 shots (for approximately 35 minutes of the 99-minute documentary), and converting that footage into stereo 3D. 

Meanwhile, the initial work at Park Road resulted in a cleaner black-and-white picture running at 24 fps for the rushes. “At the very first stage, Peter had to make a choice from hundreds of hours of footage, and all that material had to go through an initial pass in terms of speed changes and some cleanup and grain reduction,” says Bidgood. Once the shots were selected by editorial, they were pulled for more intensive work.


Restoration and Colorization 

Stereo D began collaborating with Jackson three years ago on a proof-of-concept test, working under the direction of WingNut Films, particularly in the colorization phase. Stereo D ended up handling three phases of the project: restoration, color creation and stereoscopic 3D conversion. “If it was a shot we were taking from the beginning to the end of the process, we performed a full restoration,” says Mark Simone, overall producer at Stereo D, and this includes fixing all the scratches, the heavy grain and missing frames. “For us, the major challenge of this project was figuring out how to retain or unearth as much of the original quality and resolution of the footage as possible. Oftentimes this would lead us to fully reprocessing shots once we had discovered a new technique that yielded encouraging results. Peter really instilled a sense of importance that we do all we could to honor the original material, even if it took multiple iterations to get it right.” 

Using proprietary and commercial tools, the group began the restoration process, cleaning the footage, removing dust, scratches, tears, chemical splotches and other defects, and repairing the black-and-white footage. This included removing the grain, which was fairly large, and then giving it consistency. Overall, the state of the footage varied; some of it was remarkably clean, while most of it was in dire shape.

There were instances when entire frames could not be used, requiring the artists to “cut” a usable portion of an image and use it to “patch” that part of a degraded frame. “You can fill in holes in the footage, but you have to be careful. You don’t want to be making up things in the frame that weren’t there to begin with,” says Wayne Stables, Weta Digital VFX supervisor, who acted as quality control between Stereo D and Jackson. “You take your best and hopefully well-researched and educated guess as to what might be there.” 

As part of this transformation process, the artists also retimed the footage based on the information provided by Park Road. Then they painted out the artifacts that occurred from stretching the frames, similar to what they have to do during a stereo conversion process. 

Once the group had a good restored frame, they embarked on the colorization – in this case, a maiden voyage by the well-known stereo 3D conversion facility. What people may not know, says Simone, is that there’s core processes that are shared between stereo and colorization,  namely roto. In all, more than 400 artists rotoscoped every object in every frame – from a soldier’s hat to their gun. Hundreds and hundreds of shapes were isolated so the color of each object could be determined and controlled. 

Meanwhile, the team colorized a representative keyframe, and once it was approved, then that became their guide for the moving frames when the roto work was finished.

“We spent a lot of time creating tools to deal with the volume of material and all the roto shapes each shot would have. We needed to organize and control that volume,” says Simone. To this end, the studio built a proprietary tool, called the Palette tool, that enabled the artists to work with a large amount of roto data in a way that was manageable. “Then once we nailed down the color of the objects, we could use the Palette tool and apply the color decisions from one shot across moving footage to another shot.” 

Indeed, film colorization has been in existence for quite some time, and at times has generated controversy when typical color washes are used on a film that a director purposely shot in black and white. However, this situation is different in that the cameramen at the time had no choice beyond black-and-white film; further, it was being authentically colored, presenting it as it would have been all those years ago. 

Insofar as this restored footage is old, it is now far from desaturated. Rather, the colors are bright and vibrant, just as they would have been in the real world. And, they are as historically accurate as possible, requiring meticulous research. “We were very diligent, down to the uniform patches and the red piping around the German uniforms,” says Stables. “For a building, we did a lot of research on, say, what the bricks looked like in that part of Belgium. Peter even went out and found some of the locations and photographed the environments so we could see the types of trees there. Plus, we have a massive collection of actual WWI items, from uniforms to weaponry, pretty much everything you can imagine. Peter wanted to make sure we were incredibly accurate with all the colors and details.”

Stereo, Grading and Sound

Once Jackson signed off on the 2D colorized image from Stereo D, Park Road carried out an extensive color treatment, concentrating on the historical accuracy by referencing actual uniforms and physical artifacts in the grading suite. The colored footage was often further enhanced by re-comp’ing light and shade from the restored black-and-white shots. This technique of relighting was the finishing touch that enabled the depth and atmosphere to be realized, says Wear.

The graded shots were then sent back to Stereo D for stereo conversion. Meanwhile, while Stereo D was working on the colorized imagery, Park Road similarly restored/retimed/color-graded the black-and-white footage that appears in an earlier segment of the film. 

Park Road also completed the final color grade and final sound mixing. Professional lip readers watched the footage and offered their opinion as to what was being said in the shots. Then, more than 300 hours of previous recordings of WWI vets were scrubbed to locate those plausible words, which included accents that correlated with specific regiments in the clip. In the end, between 250 and 300 actual WWI vets can be heard recounting their experiences in the film. 

“What most of us see from footage of WWI is black-and-white, old, jerky, silent, heavily degraded film, and it puts you in a mind space that this [event] happened on a different planet and during a different time, with different people. This film reminds us that it didn’t happen that long ago, and [it happened] with people like us,” says Stables. Adds Jackson, “Restoration is humanizing because it brings out the humanity of the people who were there. This movie brings these people back into our lives again.”