Reality: Film doesn’t see “RGB.” It reacts to the full spectrum of light (360–780nm).
Simulation: We reverse-engineer your digital RGB into a 43-band spectrum using the dye sensitivity controls to estimate the potential for Silver Halide to become Metallic Silver and which dictate where the Emulsion dyes form. This ensures physically correct light distributions.

👉 Why it matters: Different films stocks “see” different parts of the spectrum.

Once we map where activation will probabilistically occur for silver we adjust the shape of the density response the the HD curves, taking what was once a linear Scene exposure mapping and shaping it so the shadows hang on longer and the highlights roll off nicely.

Additionally it is during this step that texture is calculated. Grain is introduced by inciting random points in which Silver Halide that should have activated fails to activate and thus will leave create a slightly different density than the area around it. Halation draws upon the orginal exposure intensity map that was created and models locations where backscattering light that bounced back thru the stocks would have effected the exposure. Leaving a slight redish halo bleeding into the edges surrounding highlights.

👉 Why it matters: This is why film has graceful highlight rolloff and rich shadows, instead of the linear clipping you get from digital sensors and grain is natural and built into the responsive activation of the silver.

Dyes (cyan, magenta, yellow) are simulated as asymmetric Gaussian absorption curves, matchable to real film chemistry.

👉 Why it matters: Real film is all about these dyes and understanding how they block light. Density being what wavelenghts they absorb and Transmission being what they let pass thru… What we see at the end of the process is the Transmission of the Projector light that remains…

Controls at this stage effect our latent image development as we process the metallic silver in preparation for developing our dye emulsions. Push Pull is the most common adjustment tweaking the time that film stock would sit in the developer agent allowing more or less dye to form where the metallic silver is present.

1. Bleach Bypass - Controls how much of the metalic silver is washed away or retained during the development process.

2. Midtone Expansion, Developer Competition, Chroma Expansion, Dye Inhibition, Spectral Seperation - are all various subtle adjustments that account for various aspects of stock design and development processes to create the richest tones and colors.

3. Bias Controls - These are per layer adjustments to the main bleach bypass controls.

After developing our stocks and converting the metallic silver into the wavelength blocking dyes we model with transmission thru medium using Beer’s Lambert Law. The controls here allow for you to design the color/tint of the light along with it’s power. What you see on the screen is the your original input colors, or the dye colors, but rather it is the light that remains after simulating it passing thru the composite dyes and their relative density/transparency.