Soft light created by diffusing hard light sources through diffusion materials like Lee 216 or silk frames, producing gradual shadow transitions (10–50 cm) instead of hard edges.
Technical Details
Professional diffusers operate with light scattering between 40° and 180°, with Lee Filters 216 (White Diffusion) offering 60° scattering at 52% light transmission. Rosco 3006 Tough White Diffusion achieves 70% transmission with complete shadow fill from 1.2 meters distance to the light source. State-of-the-art LED panels like the Arri SkyPanel S360-C integrate variable diffusion through electronically controlled microlens arrays with scattering angles from 15° to 60°. Ripstop nylon silk diffusers achieve temperature resistance up to 200°C and are suitable for HMI lights up to 18kW.
History & Development
Georges Méliès already used silk fabrics for light diffusion in his glasshouse studio in Montreuil in 1902. Systematic development began in 1915 with Cecil B. DeMille's use of stretched linen sheets for portrait shots. In 1927, the Mole-Richardson Company developed the first industrial diffusion frames. Lee Filters revolutionized the industry in 1967 with heat-resistant polyester diffusers. Chimera introduced collapsible softboxes in 1982, enabling diffusion directly at the light head.
Practical Use in Film
Roger Deakins used massive 12x12-foot silk setups in "Blade Runner 2049" (2017) to diffuse the harsh Nevada sun rays for the farm sequences. Emmanuel Lubezki achieved characteristic naturalism in "The Revenant" (2015) by exclusively using available light with strategically placed 8x8-foot Ultrabounce reflectors. For interior shots, book lights (HMI through diffuser onto a white wall) provide eye-friendly illumination without makeup touch-ups between takes.
Comparison & Alternatives
Hard light creates defined shadows with transition widths under 2cm, while diffused light creates shadow transitions of 10-50cm. Bouncing (indirect light) reduces intensity by 1-2 stops, diffusion by 0.5-1.5 stops depending on the material. LED walls like those from Industrial Light & Magic are increasingly replacing traditional diffusion with programmable light distribution. Practical lights combined with invisible diffusion create authentic atmosphere without discernible film lighting.