Product Overview

Introduced in the 1990s, the Contax G system was one of the few 35mm camera systems to combine rangefinder viewing with autofocus operation. Developed jointly by Contax and Carl Zeiss, the system featured a lineup of Zeiss T* coated lenses covering a wide range of focal lengths. Among them, the 35mm and 45mm lenses became the most popular choices thanks to their compact size and balanced optical performance.

The G35, based on a classic Planar design, offers a natural field of view well suited for documentary and everyday photography, while the G45 is known for its high resolution and focused rendering. Both lenses remain highly regarded for their consistent and reliable image quality.

Design Concept

As digital photography became dominant, Contax G camera bodies gradually fell out of regular use, but the optical value of G-series lenses has never been overlooked. Many G-series users are also Leica M photographers, and the G35 in particular has long been considered a highly suitable focal length for the Leica rangefinder system.

Earlier conversion methods often required irreversible modifications to the original lens structure, compromising both integrity and long-term value. 

In August 2019, Funleader collaborated with MrDing Studio to introduce a non-destructive conversion solution for the Contax G35. The goal was to preserve the original optical assembly while enabling practical and intuitive use on Leica M cameras. By installing the original optical block into a dedicated Conversion Helicoid, users with basic mechanical skills can complete the conversion and achieve reliable rangefinder coupling, resulting in an experience close to that of native Leica M lenses.

Building on this approach, Funleader released a non-destructive conversion solution for the Contax G45 in May 2021. In addition to preserving the optical design, the external appearance was refined with vintage-inspired elements to better integrate visually with the Leica M system.

Technical Notes

Due to conservative demand estimates at the time of its initial release, the first-generation G35 conversion kit sold out quickly. Over the following years, Funleader continued to receive inquiries regarding a potential reissue. Based on accumulated user feedback, the decision was made to relaunch the G35 conversion kit in 2024 with substantial mechanical improvements.

The new generation features a significantly revised internal structure, with particular emphasis on focus damping and mechanical smoothness. When operating the focus lever, users will notice a more fluid, consistent, and controlled movement, enhancing precision during actual shooting rather than focusing solely on specification completeness.

Compatibility & Notes

•Designed for use with original Contax G optical assemblies, with no optical modification.

•Fully supports rangefinder coupling on Leica M cameras.

•When the aperture ring is set to f/16, the effective aperture is approximately f/13. When rotating back from f/16 to f/11, the aperture remains at f/13 and must be reset by rotating from f/8 to f/11.

This behavior is caused by structural limitations of the original optical assembly. After evaluation, priority was given to improved focus damping and overall handling, as f/16 is rarely used in practical shooting scenarios.