Grotesque & Unforgiving - The Orthochromatic Look
When I first watched Robert Eggers film The Lighthouse (2019) I was mesmerised by the way in which the characters' skin tones were so grotesque and unnatural. It wasn’t typical of black and white negatives or prints to alter skin tones in such a dramatic way yet here I was watching frame after frame of a scene completely devoid of life.
It was only after reading an interview with cinematographer Jarin Blaschke in the ASC that I understood what I was actually looking at - not a stylistic choice made in the grading suite but a photochemical reality that filmmakers had spent decades trying to escape. Orthochromatic film stock doesn't flatter. It never did. And the more I understood about why, the more I wanted to know if I could bring that same unforgiving quality into a digital pipeline.
Blinded To Red
Before the 1920s, all motion picture film was orthochromatic. The emulsion was sensitive to blue and green light but largely blind to red. This sounds like a technical footnote until you consider what it means for a human face.
Skin - warm, red-toned, alive — left almost no exposure on the negative causing it to render as dark, dense and weathered on the final print. The world, rendered through orthochromatic stock, looked nothing like the world as we experience it.
Panchromatic stock, which became the industry standard through the late 1920s, corrected this. It was sensitive across the full visible spectrum and rendered skin the way audiences expected—luminous, warm, and present.
When Eggers and Blaschke chose to shoot The Lighthouse, their decision to pursue an orthochromatic quality wasn't born out of vintage nostalgia; it was deeply purposeful. Because a true, physical orthochromatic motion picture stock no longer exists in a format they could shoot, they had to engineer their own. They chose a modern panchromatic stock - Eastman Double-X 5222 - and paired it with custom short-pass filters manufactured by Schneider Optics. By completely eliminating all light wavelengths above 570 nanometers, they effectively blinded the modern film to the entire red spectrum right at the lens.
They weren't just changing the aspect ratio or selecting vintage glass; they were physically forcing a modern stock to behave with that same unforgiving, early-century chemistry.
The Digital Process
To authentically emulate the photochemical behavior of an orthochromatic negative, I constructed a scene-referred linear pipeline designed to bypass the limitations of standard digital grading tools. Using a conventional colour print profile - like a Kodak 2383 - on a monochrome signal introduces unpredictable colour shifts due to the print's internal channel cross-talk. Conversely, simply placing a global desaturation node at the front of the tree carries flat, digital channel relationships all the way through the pipeline. To achieve total colourimetric control, I eliminated colour prints entirely and decoupled the workflow into two distinct stages: a low-contrast digital negative and a high-contrast positive print.
I began by establishing strict boundaries for the digital negative. First, I locked in a native control gamma limit of 0.650 (Image01), and a pivot point of 0.336 to anchor middle gray. This pre-compresses the scene's dynamic range, preventing highlights from clipping early and ensuring smooth tonal gradation into the lower highlights and upper shadows. Without the 0.650 negative control gamma anchoring the highlights and shadows, the pipeline loses its protective cushion.
The blue and green frequencies are forced directly into the steep positive print curve, resulting in a harsh, brittle digital image where midtone gradations shatter and highlights clip flat.
Next was the core component of the look design: the spectral matrix.
Using an absolute monochrome RGB mixer pass at the very front of the chain, I set the red channel to 0.00, while re-weighting the remaining luminance to 0.30 Green and 0.70 Blue. This completely blinds the pipeline to red frequencies while forcing the image to interpret the green and blue wavelengths with historical accuracy. Because human skin and foliage reflect heavy green light, the green channel dictates our core luminosity and structural definition, while the heavy blue bias darkens skin tones, shatters all modern beauty standards, and aggressively adds micro-textures.
A direct comparison between a standard panchromatic rendering (left) and a true orthochromatic spectral matrix completely stripped of the red channel (right).
While the adjustments appear subtle at a glance, the tonal consequences are profound. Without the red channel to flatter the complexion, the skin tones drop in value, the lips turn an ink-like dark tone, and the face takes on a raw, weathered texture. It is a striking visual proof of how heavily a modern monochrome image relies on hidden red wavelengths and what happens when you cut them out entirely.
This strict channel separation became incredibly powerful when designing the film grain. Even though the final viewing state is entirely monochromatic, the underlying mathematics of the scene-referred signal still treat the RGB channels independently. Because our matrix zeroed out the red channel, no grain texture can exist there. Instead, I targeted the unique physical characteristics of the green and blue emulsion layers. Green grain lives predominantly in the mid-tone luminance of the frame, providing a tactile structure, while blue grain naturally settles into the deeper shadow densities. While the blue grain is almost imperceptible on its own, omitting it destroys the micro-contrast and crucial shading that takes place where the shadows meet the lower mid-tones. The result is not a flat digital overlay, but a structural texturing that feels genuinely embedded within the physical silver-halide emulsion layers of the frame.
With the 0.650 negative foundation cleanly established, the final stage feeds this flat, raw log density into a dedicated 'positive print' node. Here, I applied a steep S-curve to simulate a high-contrast black-and-white release positive stock. This high-gamma curve stretches the compressed mid-tones of the negative, resulting in a rich, charcoal-like rendering where the transition from light to dark is gradual and atmospheric. By keeping the pipeline entirely scene-referred and modular, the density can be dialed up or down to a cinematographer's taste, offering a beautifully unforgiving, historically honest alternative to modern black-and-white.
From left to right - RAW to final orthochromatic rendering.
