This listing is for a classic Carl Zeiss Biogon 21mm f/4.5 ultra-wide-angle lens kit, complete with its original Zeiss Ikon 435 external viewfinder and leather lens case. This is a legendary lens from the golden era of German optics, designed for the Contax rangefinder system. This true wide-angle Biogon design is known for its exceptional lack of distortion and stellar image quality, making it a highly desirable lens for collectors and photographers alike.

Technical Specifications:

• Lens Mount: Contax bayonet mount (external).

• Focal Length: 21mm.

• Maximum Aperture: f/4.5.

• Minimum Aperture: f/22.

• Optical Design: 6 elements in 5 groups.

• Angle of View: 90 degrees.

• Filter Size: 40.5mm.

• Minimum Focus Distance: 0.9 meters.

• Year of Production: Produced from 1954 to 1961.

Condition Report: The lens is in very good cosmetic condition with clean glass and no visible signs of fungus or haze. Focusing is smooth and the diaphragm blades are clean and function correctly. The external viewfinder is clear and in good condition. The leather lens case shows signs of wear consistent with its age.