Film Color Science Lab emulates the color reproduction characteristics of analog photographic film stocks. Unlike digital sensors with uniform spectral response, each film stock has unique spectral sensitivity curves for its red, green, and blue layers that give it a distinctive color signature — the warm skin tones of Kodak Portra, the vivid saturation of Fuji Velvia, or the muted palette of Kodak Tri-X.
The shader models the film imaging chain: scene light is filtered through spectral sensitivity curves, producing latent image densities that are processed through characteristic curves (H&D curves) mapping exposure to density. Inter-layer color cross-talk and dye coupling effects reproduce the complex color interactions in real multi-layer film. Halation (light scatter through the film base) adds the characteristic glow around highlights.
Film grain is modeled with spatially varying noise calibrated to match the granularity of specific film stocks. Interactive controls select film stock presets and adjust exposure, development push/pull, and grain intensity.