Biogon 21mm f4.5, Rangefinder Contax mount. This ultra-wide-angle lens was supplied for use with the Contax IIa and IIIa cameras. Made by Carl Zeiss after the war. The distance scale is in feet. This particular lens was shipped in April 1952.

It has a symmetrical design with a large rear element that protrudes, so it cannot be mounted on M-mount cameras via an adapter. Additionally, there is a potential for interference with other digital cameras, so please handle with care when mounting.

While there are some limitations, this post-war Zeiss lens is highly regarded for its exceptional rendering and remains a favorite for its optical performance from its era.

This lens shows no signs of use and the chrome finish is beautifully shiny, making it an outstanding example both in terms of appearance and glass condition.

A full overhaul was completed in April 2025. The operation of the aperture ring and helicoid is very smooth, with a perfect amount of torque.

In addition to its beautiful appearance, the glass is free from cleaning marks. Furthermore, there is no haze or coating damage, which is often seen with the Biogon 21mm. The glass is exceptionally clear and sharp, offering a pristine optical experience.

This lens will allow you to fully enjoy the remarkable rendering characteristic of the Biogon.

It comes with the original matching plastic case, an aluminum Carl Zeiss-branded lens cap, and even the cardboard that sits between the lens cap and the plastic case. This lens is in an extremely rare condition and would make an excellent addition to any collection.