Premium lens series by Kowa featuring fluorite-type glass elements for maximum sharpness and color accuracy.
Technical Details
Kowa Prominar lenses operate with a 2.0x squeeze factor and cover focal lengths from 40mm to 200mm. The construction is based on a spherical primary lens with attached cylindrical elements for horizontal compression. Typical apertures range from f/2.8 to f/4.0. The lenses use a special Kowa bayonet mount, which was later expanded with adapters for standard camera systems. The optical construction comprises 12-16 lens elements in 8-10 groups, with the cylindrical elements made from specially ground optical glass.
The characteristic bokeh is created by the oval distortion of light sources in the out-of-focus areas. Horizontal blue streaks (Anamorphic Flares) occur with strong light sources and are caused by the cylindrical optics.
History & Development
Kowa developed the first Prominar lenses in 1954 in response to 20th Century Fox's Cinemascope system. The company, originally a specialist in binoculars and telescopes, leveraged its expertise in precision optics for the film market. In 1958, Kowa introduced the 8Z series, which was specifically adapted for Panavision cameras.
Production ended in 1982, as electronic image processing and modern lens designs supplanted mechanical anamorphic lenses. Today, Kowa Prominar lenses are considered sought-after vintage optics for characteristic Cinemascope looks.
Practical Use in Film
Sergio Leone used Kowa Prominar lenses for his Western films of the 1960s, including "A Fistful of Dollars" (1964). The lenses enabled extreme wide-angle shots with characteristic distortion at the image edges. Akira Kurosawa employed 200mm Prominar lenses for telephoto shots in "Kagemusha" (1980).
The workflow requires precise calibration, as different focal lengths exhibit different distortion characteristics. Focus is adjusted on the spherical primary lens, while the anamorphic elements remain fixed.
Comparison & Alternatives
Kowa Prominar lenses differ from Panavision Anamorphic lenses due to stronger chromatic aberrations and less uniform illumination. Compared to Isco Ultra Star lenses, they offer softer bokeh transitions but lower sharpness in the image corners.
Modern alternatives like Cooke Anamorphic/i or ARRI Master Anamorphic achieve higher optical precision but forgo the characteristic aberrations of vintage optics. For an authentic Cinemascope aesthetic, Kowa Prominar lenses remain irreplaceable.