NBCUni 9.5.23

Color grading Togo with an Autochrome-type look

Before principal photography began on the Disney+ period drama Togo, the film’s director and cinematographer, Ericson Core, asked Company 3 senior colorist Siggy Ferstl to help design a visual approach for the color grade that would give the 1920s-era drama a unique look. Based on a true story, Togo is named for the lead sled dog on Leonhard Seppala’s (Willem Dafoe) team and tells the story of their life-and-death relay through Alaska’s tundra to deliver diphtheria antitoxin to the desperate citizens of Nome.

Siggy Ferstl

Core wanted a look that was reminiscent of the early color photography process called Autochrome, as well as an approach that evoked an aged, distressed feel. Ferstl, who recently colored Lost in Space (Netflix) and The Boys (Amazon), spent months — while not working on other projects — developing new ways of building this look using Blackmagic’s Resolve 16.

Many of Ferstl’s ideas were realized using the new Fusion VFX tab in Resolve 16. It allowed him to manipulate images in ways that took his work beyond the normal realm of color grading and into the arena of visual effects.

By the time he got to work grading Togo, Ferstl had already created looks that had some of the visual qualities of Autochrome melded with a sense of age, almost as if the images were shot in that antiquated format. Togo “reflects the kind of style that I like,” explains Ferstl. “Ericson, as both director and cinematographer, was able to provide very clear input about what he wanted the movie to look like.”

In order for this process to succeed, it needed to go beyond the appearance of a color effect seemingly just placed “on top” of the images. It had to feel organic and interact with the photography, to seem embedded in the picture.

A Layered Approach
Ferstl started this large task by dividing the process into a series of layers that would work together to affect the color, of course, but also to create lens distortion, aging artifacts and all the other effects. A number of these operations would traditionally be sent to Company 3’s VFX department or to an outside vendor to be created by their artists and returned as finished elements. But that kind of workflow would have added an enormous amount of time to the post process. And, just as importantly, all these effects and color corrections needed to work interactively during grading sessions at Company 3 so Ferstl and Core could continuously see and refine the overall look. Even a slight tweak to a single layer could affect how other layers performed, so Ferstl needed complete, realtime control of every layer for every fine adjustment.

Likewise the work of Company 3 conform artist Paul Carlin could not be done in the way conform has typically been done. It couldn’t be sent out of Resolve and into a different conform/compositing tool, republished to the company network and then returned to Ferstl’s Resolve timeline. This would have taken too long and wouldn’t have allowed for the interactivity required in grading sessions.

Carlin needed to be able to handle the small effects that are part of the conform process — split screens, wire removals, etc. — quickly, and that meant working from the same media Ferstl was accessing. Carlin worked entirely in Resolve using Fusion for any cleanup and compositing effects — a practice becoming more and more common among conform artists at Company 3. “He could do his work and return it to our shared timeline,” Ferstl says. “We both had access to all the original material.”


Most of the layers actually consisted of multiple sublayers. Here is some detail:
Texture: This group of sublayers was based on overlaid textures that Ferstl created to have a kind of “paper” feel to the images. There were sublayers based on photographs of fabrics and surfaces that all play together to form a texture over the imagery.
Border: This was an additional texture that darkened portions of the edges of the frame. It inserts a sense of a subtle vignette or age artifact that framed the image. It isn’t consistent throughout; it continually changes. Sublayers bring to the images a bit of edge distortion that resembles the look of diffraction that can happen to lenses, particularly lenses from the early 20th century, under various circumstances.
Lens effects: DP Core shot with modern lenses built with very evolved coatings, but Ferstl was interested in achieving the look of uncoated and less-refined optics of the day. This involved the creation of sublayers of subtle distortion and defocus effects.
Stain: Ferstl applied a somewhat sepia-colored stain to parts of the image to help with the aging effect. He added a hint of additional texture and brought some sepia to some of the very bluish exterior shots, introducing hints of warmth into the images.
Grain-like effect: “We didn’t go for something that exactly mimicked the effect of film grain,” Ferstl notes. “That just didn’t suit this film. But we wanted something that has that feel, so using Resolve’s Grain OFX, I generated a grain pattern, rendered it out and then brought it back into Resolve and experimented with running the pattern at various speeds. We decided it looked best slowed to 6fps, but then it had a steppiness to it that we didn’t like. So I went back and used the tool’s Optical Flow in the process of slowing it down. That blends the frames together, and the result provided just a hint of old-world filmmaking. It’s very subtle and more part of the overall texture.”

Combining Elements
“It wasn’t just a matter of stacking one layer on top of the other and applying a regular blend. I felt it needed to be more integrated and react subtly with the footage in an organic-looking way,” Ferstl recalls.

One toolset he used for this was a series of customized lens flare using Resolve’s OFX, not for their actual purpose but as the basis of a matte. “The effect is generated based on highlight detail in the shot,” explains Ferstl. “So I created a matte shape from the lens flare effect and used that shape as the basis to integrate some of the texture layers into the shots. It’s the textures that become more or less pronounced based on the highlight details in the photography and that lets the textures breathe more.”

Ferstl also made use of the Tilt-Shift effect in Fusion that alters the image in the way movements within a tilt/shift lens would. He could have used a standard Power Window to qualify the portion of the image to apply blur to, but that method applied the effect more evenly and gave a diffused look, which Ferstl felt wasn’t like a natural lens effect. Again, the idea was to avoid having any of these effects look like some blanket change merely sitting on top of the image.

“You can adjust a window’s softness,” he notes, “but it just didn’t look like something that was optical… it looked too digital. I was desperate to have a more optical feel, so I started playing around with the Tilt-Shift OFX and applying that just to the defocus effect.

“But that only affected the top and bottom of the frame, and I wanted more control than that,” he continues. “I wanted to draw shapes to determine where and how much the tilt/shift effect would be applied. So I added the Tilt-Shift in Fusion and fed a poly mask into it as an external matte. I had the ability to use the mask like a depth map to add dimensionality to the effect.”

As Ferstl moved forward with the look development, the issue that continually came up was that while he and Core were happy with the way these processes affected any static image in the show, “as soon as the camera moves,” Ferstl explains, “you’d feel like the work went from being part of the image to just a veil stuck on top.”

He once again made use of Fusion’s compositing capabilities: The delivery spec was UHD, and he graded the actual photography in that resolution. But he built all the effects layers at the much larger 7K. “With the larger layers,” he says, “if the camera moved, I was able to use Fusion to track and blend the texture with it. It didn’t have to just seem tacked on. That really made an enormous difference.”

Firepower
Fortunately for Ferstl, Company 3’s infrastructure provided the enormous throughput, storage and graphics/rendering capabilities to work with all these elements (some of which were extremely GPU-intensive) playing back in concert in a color grading bay. “I had all these textured elements and external mattes all playing live off the [studio’s custom-built] SAN and being blended in Resolve. We had OpenFx plugins for border and texture and flares generated in real time with the swing/tilt effect running on every shot. That’s a lot of GPU power!”

Ferstl found this entire experience artistically rewarding, and looks forward to similar challenges. “It’s always great when a project involves exploring the tools I have to work with and being able to create new looks that push the boundaries of what my job of colorist entails.”


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