Mr. Ding Contax G35/2 Conversion V2.1

Mr. Ding Contax G35/2 Conversion V2.1

The Mr. Ding Contax G35/2 Conversion V2.1 installs the original Carl Zeiss Planar T* 35mm f/2 optical assembly from the Contax G system in a manual-focus Leica M barrel. The system is designed as a reversible, non-destructive conversion: the Zeiss optical block is removed from its autofocus housing without changing the glass and placed in a new helicoid with an M bayonet and mechanical rangefinder cam. Mr. Ding offers both conversion kits and complete pre-converted lenses.

The donor lens uses seven elements in five groups, an actual focal length of 35.1mm, T* antireflection coating, an f/2 to f/16 aperture range, an M46 by 0.75 filter thread, and a 0.5-metre original close-focus limit. The current V2.1 conversion uses aluminum for the outer housing and brass for the internal focus helicoids. Mr.Ding lists 177g for the kit, 233g with glass, a 46mm filter fitting, and rangefinder focusing. The page also notes that the converted mechanism reaches approximately f/13 when the ring is set to f/16.

This profile is specific to Mr. Ding V2.1. It shares development history with Funleader and earlier Mr. Ding versions, but remains a separate commercial product. Other G35 conversions can use different housings, cams, materials, focusing travel, and support even when their donor optics are identical.

Optical qualities

Rendering

The conversion retains the Planar T* 35mm f/2 optical formula, so its basic image formation comes from the original seven-element, five-group Zeiss design. Rehousing changes the focusing and mounting mechanics rather than the optical calculation. Correct seating, centring, and shimming remain essential; a tilted or incorrectly spaced optical block can perform differently from the donor lens's published data.

Zeiss designed the 35mm lens as a compact medium wide-angle for the 24 by 36mm Contax G system. At f/2, rangefinder calibration and field behaviour are easier to see than when stopped down. A specific conversion should be tested before broad performance claims are made.

Contrast and flare

The original T* coating remains part of the optical block. Contrast still depends on surface condition, internal baffling, and the quality of assembly in the new barrel. A 46mm hood may help with oblique light, provided it does not intrude excessively into the Leica finder. Haze or cleaning marks in a donor lens are not corrected by conversion.

Out-of-focus rendering

The f/2 aperture permits subject separation at closer distances while retaining a 35mm documentary field. The original diaphragm is retained, so rehousing does not create a new bokeh formula. Highlight shape and transition character depend on aperture, distance, background structure, and the donor assembly. They should be evaluated from known images rather than generalized from the Planar name.

Rangefinder and digital use

The Leica M cam provides coupled focusing on a calibrated body. The usable coupled range may differ from the donor's 0.5-metre autofocus specification; Mr.Ding does not state a separate V2.1 minimum in the cited data. Mirrorless adaptation adds no electronics, autofocus, or aperture metadata.

History

Development and Launch

Carl Zeiss introduced the Planar T* 35mm f/2 with the Contax G2 generation in 1996. The original lens relied on the Contax G camera's electronic autofocus drive. Its compact optical unit remained useful after the camera system ended, but Leica M use required a purpose-built manual helicoid and a calibrated rangefinder cam.

Funleader and Mr.Ding Studio introduced their first non-destructive G35 conversion in August 2019. The stated goal was to retain the complete optical assembly while replacing the original focusing structure with a dedicated Leica M mechanism. This made the conversion reversible and separated it from earlier solutions that permanently altered donor components.

Production Evolution

The conversion evolved through later housings, including an all-brass V2.0 and the current V2.1. Mr.Ding describes V2.1 as the lightweight successor, replacing much of the outer brass with high-strength aluminum while retaining brass-on-brass internal helicoids. The complete listed weight fell from 312g for V2.0 to 233g for V2.1, while both versions retained a 46mm front fitting and rangefinder coupling.

The current aperture note also matters: when the ring is set to f/16, the mechanism produces an effective opening of about f/13. This is a conversion-specific limitation and should not be confused with the donor Zeiss specification, which lists f/16. Version and assembly source therefore affect the finished lens's mechanical record even though the glass remains unchanged.

Special Editions/Variants

V2.0 was offered in black and silver, while the current V2.1 listing specifies black. Kit-only and complete-lens options also differ in what the buyer receives. Earlier collaboration versions and unrelated third-party G35 rehousings are separate commercial products, not cosmetic variants that should automatically be merged with this profile.

Collector Notes

Document the donor optical block and the conversion version separately. Verify infinity, rangefinder agreement at several distances, aperture operation, and smooth helicoid travel. A self-installed kit can be optically excellent yet poorly calibrated if shimming or seating is incorrect. Live view provides a useful check against rangefinder error.

Reversibility assumes that the original Contax housing and small parts were retained. A complete pre-converted lens includes original G35 glass, while a kit alone does not.