Reconstruct the light
Reality: film reacts to the full 360–780nm spectrum, not just “RGB.”
We reverse-engineer your digital RGB into a 43-band spectrum using the dye-sensitivity controls. That estimates where silver halide is likely to become metallic silver, and which emulsion dyes form where, giving physically plausible light distributions to work from.
Different film stocks “see” different parts of the spectrum. Get this right and everything downstream behaves like real film.