Funleader Contax Planar 35mm f/2 Conversion V2

Funleader Contax Planar 35mm f/2 Conversion V2.0

The Funleader Contax Planar 35mm f/2 Conversion V2.0 is a second-generation Leica M rehousing of the Carl Zeiss Planar T* 35mm f/2 optical block from the Contax G system. It preserves the original Zeiss optics while replacing the Contax autofocus housing with a purpose-built manual focusing barrel that couples mechanically to the Leica M rangefinder.

V2.0 follows the first Funleader and Mr Ding non-destructive G35 conversion introduced in 2019. Rather than changing the optical formula, the development programme concentrated on the mechanical behaviour of the conversion after several years of practical use.

The original Carl Zeiss optical assembly consists of seven elements in five groups with a seven-blade diaphragm. Funleader states that the optical block is transferred without optical modification, making V2.0 a rehousing and focusing-system redesign rather than a newly calculated 35mm lens.

The complete V2.0 lens measures approximately 54mm in diameter and 39mm in length and weighs approximately 312g in the documented brass configuration. It accepts 46mm filters and focuses to 0.7m.

The lens is mechanically rangefinder-coupled throughout its normal Leica M focusing range.

One specific mechanical characteristic concerns the smallest marked aperture. Funleader states that when the aperture ring is set to f/16, the actual effective aperture is approximately f/13. Returning directly from the f/16 position toward f/11 can leave the diaphragm at approximately f/13 until the ring is cycled from f/8 toward f/11.

Optical qualities

Rendering

V2.0 retains the original Carl Zeiss Planar T* G35 optical block without optical modification. Its underlying rendering characteristics therefore remain associated with the original Contax G35 optical design rather than with a separate Funleader optical calculation.

Independent testing of the earlier conversion generation is relevant to the retained optical block, although mechanical alignment, rangefinder calibration and sample condition can influence the practical performance of individual converted lenses.

Sharpness

Testing of the same G35 optical generation in the earlier Funleader housing found strong central sharpness at f/2 with weaker peripheral behaviour at large apertures and long distances. Since V2.0 does not recalculate the optics, the mechanical redesign should not by itself be interpreted as an optical performance change.

Bokeh and transitions

The original seven-blade diaphragm remains part of the Contax optical assembly. The converted lens therefore retains the diaphragm geometry of the donor lens.

Distortion and vignetting

Independent testing of the retained G35 optical design shows visible vignetting at larger apertures. Peripheral performance improves as the lens is stopped down.

Digital use

V2.0 is designed to provide conventional Leica M operation with an optical block that was originally dependent on the Contax G autofocus system. Manual focusing is provided through a dedicated helicoid and focus lever, while the rangefinder-coupled construction allows optical rangefinder focusing on compatible Leica M bodies.

History

Development and Launch

The original Carl Zeiss Planar T* 35mm f/2 was developed for the autofocus Contax G system and introduced during the 1990s.

Funleader and Mr Ding Studio introduced their first non-destructive G35 Leica M conversion in August 2019. The original optical assembly could be removed from the Contax autofocus housing and transferred into a dedicated Leica M helicoid.

After the first conversion had accumulated several years of use, feedback increasingly concerned mechanical factors such as focusing resistance, stability and the way the converted lens integrated with Leica M cameras.

The Mr Ding development team began the V2.0 project in 2024. The redesigned conversion reached the market as V2.0 in 2025.

Production Evolution

The defining difference between V1 and V2.0 is mechanical rather than optical.

V2.0 introduced a redesigned internal transmission system and revised focus-damping curve intended to provide smoother and more consistent resistance through the focusing range.

Funleader also revised the exterior construction. Changes included the focusing lever, barrel grip pattern, position of the 35mm marking, typography and overall manufacturing details.

The documented complete V2.0 specification uses a brass, chrome-plated housing and weighs approximately 312g.

During 2026 Funleader also introduced an updated black conversion-helicoid configuration using aluminium-alloy exterior components to reduce weight. Contemporary documentation indicates that the fully converted lens continued to be offered with brass construction. This material change in a conversion-kit option does not alter the retained Carl Zeiss optical block.

Special Editions/Variants

V2.0 is documented in black and silver finishes.

Funleader offers both the conversion helicoid alone and a complete converted lens containing an original Contax G35 optical block. These are two purchasing configurations of the same conversion system rather than different optical lens designs.

A later black conversion-kit revision introduced lighter aluminium exterior components. The complete-lens configuration remained distinct in material specification and should be checked before assigning weight to an individual example.

Collector Notes

V2.0 must not inherit the 160g weight or approximately 31mm original barrel length of the unconverted Contax G Planar. Those figures refer to the original Contax G autofocus lens.

The documented complete Funleader V2.0 weighs approximately 312g and measures 54 × 39mm.

V2.0 should also remain separate from the original Funleader conversion. Although both use the same Carl Zeiss G35 optical block, the redesigned focusing transmission, damping system, focus lever and barrel construction form a meaningful mechanical generation change.

Mr Ding Studio also markets its own versions of the G35 conversion system. The shared development history should be documented, but a Funleader-branded commercial V2.0 product and a separately marketed Mr Ding product can remain distinct LeicaLensList profiles when their commercial identity and mechanical generation are clearly identified.