Zeiss Biotar 58mm f/2.0 — vintage prime prized for its swirly bokeh, soft rendering, and flattering portrait character.
Technical Details
The Biotar 58/2.0 weighs 285 grams with a filter diameter of 52mm. The symmetrical Gauss design consists of two three-element groups with high-refraction heavy flint glass in the inner elements. The aperture range extends from f/2.0 to f/16 with twelve blades for circular aperture openings. The minimum focusing distance is 0.6 meters, and the angle of view is 40°. The lens was originally designed for the M42 mount (Pentax mount) and was later also available for the Exakta bayonet.
History & Development
Carl Zeiss developed the first Biotar in 1927 as an evolution of the Planar design. The 58mm variant appeared in 1936 specifically for Exacta cameras and quickly established itself as a standard lens for high-end 35mm cameras. After World War II, Carl Zeiss Jena continued to produce the Biotar until 1970, while the West German Zeiss division further developed the design into the Planar 50/1.4. Production ended with the introduction of more modern multi-layer coatings.
Practical Use in Film
Cinematographer Conrad Hall used the Biotar 58 for close-ups in "In Cold Blood" (1967) to exploit its characteristic out-of-focus rendering. At wide apertures, the lens produces a soft background blur with a slight "swirly bokeh" – circular out-of-focus highlights that become oval towards the edges of the frame. Modern film productions use adapted Biotar lenses for vintage looks, especially on digital cameras, where the warm color rendition softens the sterile sensor look.
Comparison & Alternatives
The Biotar 58 differs from the later Planar in having less contrast and softer gradation. Modern alternatives like the Zeiss Planar 50/1.4 or the Leica Summilux offer higher sharpness performance but less character. The Helios 44-2, produced in the Soviet Union, is based on the Biotar design and delivers similar optical properties at a significantly lower cost. For digital productions, the Biotar is particularly suitable in available light situations where its speed and organic look are in demand.