Special lens surface treatment with multiple thin layers that reduces reflections and flare far more effectively than single-layer coating.
Technical Details
Modern multi-coatings achieve residual reflections of 0.2-0.5% per surface compared to 4% for uncoated lenses. Zeiss T* coating uses 6-10 layers, Cooke /i lenses employ 12-layer systems. The layers are applied by vacuum sputtering or electron beam evaporation at 10⁻⁶ mbar. High-quality cinema lenses like Arri Master Primes possess up to 16 lens elements with two coated surfaces each – without multi-coating, over 50% of incident light would be lost through internal reflections.
History & Development
Zeiss developed the first single coating in 1935, Kodak introduced multi-layer systems in 1946. A breakthrough for cinematography was the 1972 Zeiss T* coating for Super-Speed lenses, followed by Cooke's S4 series in 1992. Since 2000, plasma-assisted coating processes have enabled more complex layer systems with up to 20 layers. Current developments integrate nanostructures for broader-band anti-reflection.
Practical Application in Film
Cinematographer Roger Deakins used multi-coated Arri Master Primes for "Blade Runner 2049" (2017) for controlled lens flares in extreme backlight situations. The precise coating allowed for calculable light effects instead of random stray light artifacts. Wes Anderson prefers Cooke S4 for his symmetrical compositions due to their characteristic multi-coating, which delivers minimal chromatic aberrations and high sharpness. For night shots, multi-coating increases usable light output by 30-40% compared to single-coated systems.
Comparison & Alternatives
Single coating costs 60% less but offers only 1-2% residual reflection. Uncoated lenses produce significant contrast loss and ghosting. Special coatings like Arri LDS (Lens Data System) combine anti-reflection properties with metadata transmission. PVD (Physical Vapor Deposition) coatings are increasingly replacing traditional methods and enable harder, more scratch-resistant surfaces. Vintage lenses without multi-coating are intentionally used for characteristic flares and reduced contrast.