Funleader, together with Mr. Ding, announced a new Contax G28 lens-to-Leica M-mount conversion project. This project began in 2019 with the G35 and continued with the G45, with the goal of allowing classic Contax G lenses to be used on Leica M-mount cameras without permanently modifying the original lenses. The newly announced G28 conversion features a brass internal structure for durability and an aluminum exterior to reduce weight, completing a three-lens lineup that covers 28mm, 35mm, and 45mm.
Orders are now open at:
- Funleader (update: sold out already)
- Mr. Ding Studio (stil in stock)
Discount coupon codes:
- Funleader 5% off code: LEICARUMORS
- Mr. Ding Studio 5% off code: 2025YLSZMRAE
Here is an updated list of photo gear promo codes you can use during this holiday shopping season
Full details on the new lens after the break:
Lens features:
- Zero Compromise: Non-destructive conversion keeps your original G28 lens completely intact and reversible.
- Native M-Mount Experience: Installation delivers smooth, precise handling that feels exactly like a factory Leica lens.
- Smart Weight Management: Brass-aluminumhybrid construction balances premium durability with comfortable, extended shooting sessions.
- Lossless conversion. During the conversion process, there will be no damage to the original G28/2.8. In the future, if you wish to reuse the shell of G28/2.8, it can be restored for reuse. The conversion process will not affect any performance.
- Revitalize the classic Contax optics. The Contax G28/2.8 has high optical quality and a good reputation. The conversion kit can breathe new life into its ultra-high resolution and vibrant colors on Leica M.
- Combined with our specially formulated damping grease, the overall handling achieves a good balance. Letting classic design be just as comfortable to use.
- Features a lightweight aluminum exterior paired with a brass inner structure, offering both durability and smooth operation while significantly reducing overall weight.Perfect for street and documentary photography, giving you a more effortless shooting experience.
Additional information:
- Color: Black Paint
- Weight: 113g(Only Kit)
- Weight: 168g(With glass)
- Body Material: Outer aluminum, Inner Brass
- Filter Size: 46mm
- Viewfinder Focus: Yes
- Recoverable or Not: Yes
Contax G series, launched in the 1990s, stands as one of the few rangefinder systems to achieve autofocus while maintaining traditional rangefinder handling. Developed jointly by Contax and Carl Zeiss, the system featured a lineup of premium T* coated lenses. Among these, the 28mm, 35mm, and 45mm focal lengths have become the most beloved by rangefinder enthusiasts worldwide.
The G28 features a Biogon symmetrical optical design with 7 elements in 5 groups, providing a 75° wide-angle field of view. With a maximum aperture of f/2.8, minimum aperture of f/22, closest focusing distance of 0.5m, 46mm filter thread, and weighing just 150g, this lens exemplifies compact precision.
What sets the G28 apart is its remarkable barrel distortion control—a mere 0.3%, virtually negligible for a wide-angle lens. MTF charts reveal that at f/2.8, the G28’s center resolution already surpasses the legendary G45 (often hailed as the “world’s best standard lens”), with optimal performance around f/5.6 and remarkably consistent edge-to-edge sharpness.
In terms of rendering, the G28 delivers crisp, contrasty images with vivid color reproduction, particularly excelling with red tones and blues in low-light conditions—the signature Zeiss look. Even the bokeh from this wide-angle lens proves surprisingly pleasing and smooth.
Technical Notes
The G28 Leica M Conversion Kit follows the proven non-destructive conversion approach of its predecessors. Using the dedicated Conversion Helicoid, users with basic practical skills can achieve rangefinder-coupled focusing virtually indistinguishable from native Leica lenses—smooth focus travel, precise aperture damping, and seamless body integration.
Compatibility & notes:
- Designed for original Contax G optical lens groups—no optical modifications
- Supports rangefinder-coupled focusing on all Leica M bodies
- Kit does not include the optical lens group; users must provide their original G28 lens
- Conversion process is non-destructive, preserving the original lens structure
Press release:
The Story Behind the Contax G to Leica M Conversion Project
The project aims to bring classic Contax G lenses, originally designed for the Contax G autofocus rangefinder system of the 1990s, to modern Leica M cameras without permanently modifying the original lenses.
A Classic System
The Contax G system, developed by Contax and Carl Zeiss, debuted in the mid-1990s and included several well known lenses such as the Planar 35mm f/2, Planar 45mm f/2, and Biogon 28mm f/2.8. While the cameras themselves have long been discontinued, the lenses remain popular among photographers for their distinctive rendering and strong optical performance. Many photographers who own these lenses also use Leica M cameras, which has led to ongoing interest in adapting the lenses to the Leica M mount.
A Non-Destructive Approach
Rather than permanently altering the optics or original mount, the conversion kits are designed to be installed without modifying the lens itself. The optical elements and original Contax G mount remain intact.
Development Timeline
The project began in 2019 with the release of the G35 conversion kit, which adapted the Planar 35mm f/2 for Leica M cameras. While the first version proved popular and sold out quickly, the team continued refining the design. In 2021, the G45 conversion was introduced for the Planar 45mm f/2. Improvements included smoother focus damping and refinements to the internal mechanical structure. These updates later informed the release of G35 v2.0 in 2025, which featured a redesigned focusing mechanism and improved internal construction based on user feedback. The series now concludes with the G28 conversion, announced in 2026. Materials and Design For the G28 project, the team selected a combination of materials to balance durability and weight. The internal structure uses brass components for stability and longevity, while the outer housing is made from aluminum to keep the overall weight manageable.
Three Lenses for Everyday Photography
Together, the three converted lenses cover a practical focal range:
- G28 – 28mm f/2.8 Biogon (wide-angle)
- G35 – 35mm f/2 Planar (general purpose)
- G45 – 45mm f/2 Planar (standard lens)
This range, from 28mm to 45mm, is commonly used for street, documentary, and travel photography.
Continuing the Exploration
With the release of the 28mm, 35mm, and 45mm conversion kits, Funleader and Mr. Ding mark a major
milestone in the Contax G conversion project. While these three lenses represent a key stage, the team
leaves open the possibility of developing conversions for other focal lengths in the future, continuing
their mission to bring classic lenses to modern camera systems and keep vintage optics alive in the
digital era.
Related videos:
The Contax Planar 35/2 T* lens v2.0 for Leica M-mount by Mr. Ding is now available in black
The Contax G45 f/2 lens for Leica M-mount by Funleader is back in stock (limited supply)
