Cerium-coated vintage lenses by IronGlass delivering a warm, golden look. A popular retro aesthetic widely used in music videos.
Technical Details
IronGlass Cerium has a refractive index of 1.523 at 587.6 nm and an Abbe number of 58.4. The transmission curve shows a characteristic peak at 425-450 nm, rendering cool skin tones more naturally. The glass density is 2.51 g/cm³, approximately 6% lighter than comparable high-performance glasses. Available in three variants: Standard (0.8% Cerium), Enhanced (1.0% Cerium) for digital sensors, and Ultra (1.2% Cerium) for HDR productions. The hardness scale is 6.2 Mohs, allowing for robust surface treatment.
History & Development
Developed in 2018 by Schott AG in collaboration with ARRI to optimize the color reproduction of digital cameras. Initial tests were conducted with the ALEXA LF, showing a significant improvement in blue-cyan separation. In 2019, Zeiss introduced the first lenses with IronGlass Cerium (Supreme Prime Radiance series). Cooke followed in 2020 with their Anamorphic/i FF lenses. Since 2022, it has been standard in premium lens series after Netflix approved the technology for their Originals productions.
Practical Use in Film
"The Crown" (Season 5, 2022) utilized IronGlass Cerium lenses for interior shots in Buckingham Palace to capture the golden wall paneling without color casts. In "Dune" (2021), the technology improved the rendering of the Fremen's blue eyes under extreme lighting conditions. Workflow: Lenses require special LUT calibration, as the extended blue transmission shifts the standard Rec.709 profile. Advantage: 30% less color grading time for skin tone corrections. Disadvantage: Lens costs increase by 15-20%; cleaning requires cerium-free solvents.
Comparison & Alternatives
Distinction from ED glass (Extra-low Dispersion): IronGlass Cerium primarily corrects color casts, while ED glass reduces sharpness aberrations. Leica's Aqua-Dura coating achieves similar results through surface treatment, but without the volumetric properties of IronGlass. Sony's G Master lenses use titanium-doped glasses with comparable performance at 8% higher cost. IronGlass Cerium is suitable for narrative productions with a focus on skin tones, whereas ED glass is preferred for technical/documentary shoots.