Uncoated Lens

Technical Details

According to Fresnel's formulas, each uncoated glass surface reflects approximately 4% of perpendicularly incident light at a refractive index of 1.5. A typical five-element lens thus loses about 32% of its transmission. The lack of coating intensifies lens flares, ghosting, and reduces contrast to approximately 1:50 to 1:100, compared to 1:500 for modern multi-coated lenses. Stray light between lens elements generates characteristic hexagonal or octagonal reflections corresponding to the aperture shape.

History & Development

The first cinematic lenses from Zeiss and Cooke (1895-1930) were exclusively uncoated. Carl Zeiss developed the first anti-reflection coating in 1935, which was used in the T* series from 1939. Kodak introduced Ektar lenses with magnesium fluoride coating in 1940. After 1950, uncoated lenses largely disappeared from mass production, but experienced a renaissance from the 1990s for special cinematic effects in commercials and music videos.

Practical Use in Film

Derek Jarman deliberately used uncoated Cooke lenses from the 1920s for "Caravaggio" (1986) to reproduce the muted contrast of the paintings. Cinematographer Darius Khondji partially used uncoated lenses for "Se7en" (1995) to enhance the dark atmosphere through reduced contrast. In the advertising industry, DoPs specifically use uncoated lenses for soft lens flares in backlight shots. The reduced contrast lends skin tones a velvety quality, while highlights bloom gently.

Comparison & Alternatives

Compared to single-coated lenses (one layer of coating), uncoated lenses offer stronger flare effects but significantly less transmission. Multi-coated lenses (multilayer coating) achieve 95-98% transmission and eliminate flares almost completely. Pro-Mist or Black Pro-Mist filters partially simulate the look of uncoated optics on modern lenses. Vintage lenses such as Cooke Speed Panchros or Zeiss Standard Speeds from the pre-coating era today fetch collector prices of 15,000-40,000 Euros per set.