Funleader Contax Planar 45mm f/2

Funleader Contax Planar 45mm f/2

This lens is not a new optical design but a rehoming of an existing one: Funleader takes the Carl Zeiss Planar T* 45mm f/2 originally built for the autofocus Contax G system and places its optical block into a dedicated helicoid so it can be used on Leica M cameras. Funleader acquired 300 Contax 45mm f/2 lenses, originally for Contax G mount, and non-destructively converted them to Leica M mount to allow the original Carl Zeiss Planar T* optics to be used with modern Leica rangefinders. The appeal for collectors and users is twofold: it preserves a respected Zeiss normal lens intact while adding manual rangefinder operation that the Contax G bodies, with their autofocus-only handling, never offered [1][2].

The underlying optic is a classic Planar arrangement of six elements in four groups with Zeiss T* multicoating. It uses six elements in four groups and Zeiss's Planar T* multi-coated design that was appreciated for its ability to out-resolve almost all the grain from low ISO films. In the Funleader form the optical assembly is mounted into a conversion helicoid that drives the Leica rangefinder, focusing to a close distance and operating as a manual lens. By installing the optical assembly into a dedicated conversion helicoid, users with basic technical skills can complete the conversion and achieve reliable rangefinder coupling, delivering an experience close to that of a native Leica lens. The compact barrel keeps the package small and light on an M body, with a 46 mm filter thread and a six-bladed aperture from the original Contax optical unit.

The product exists both as a finished converted lens and as a helicoid kit for owners who already have the Contax G45 and want to perform the swap themselves. Because Funleader has a limited number of lenses in stock and does not know for certain if more will be acquired, the company also provided instructions on how to perform the conversion at home for photographers who already own the lens. Funleader offers it in two finishes, silver and black, matching the two-tone aesthetic of the verified record [2].

Optical qualities

Rendering The optical signature is that of the original Contax G Carl Zeiss Planar 45mm f/2, since the conversion does not alter the glass. Funleader states that optical performance remains consistent with the original Contax G45 lens. The Planar T* normal lens was regarded in its era as one of the stronger performers of its type. It was one of the sharper normal lenses made at the time, with its T* multi-coated design appreciated for its ability to out-resolve almost all the grain from low ISO films. The lens is notable for its color reproduction. Detailed test data specific to the converted M-mount version is limited, so claims about bokeh, flare, distortion, and digital corner behavior are best treated cautiously rather than asserted.

History

Development and Launch The lens originates in the Contax G system rather than the Leica world. The Contax G series was introduced in the 1990s as one of the few 35mm camera systems to combine rangefinder viewing with autofocus operation; developed jointly by Contax and Carl Zeiss, the system featured multiple Carl Zeiss T* coated lenses, among which the 35mm and 45mm lenses became the most popular focal lengths. The original Contax Zeiss Planar 45mm f/2 was an autofocus lens designed for the Contax G1 and G2 cameras. Within that system the 45mm held a particular reputation. The G45 is known for its high resolution and image concentration.

Production Evolution Funleader's conversion program developed in stages. In August 2019, Funleader collaborated with Mr Ding Studio to introduce a non-destructive conversion solution for the Contax G35, the goal being to allow G-series lenses to be used on Leica M cameras without altering the original optical block. This was not the first time Funleader had re-mounted a Contax lens; in 2019 it acquired and converted 170 Contax 35mm lenses, and after that success decided to do it again in larger numbers with the 45mm f/2. Building on the earlier approach, Funleader released a non-destructive conversion solution for the Contax G45 in May 2021, incorporating a vintage-inspired design language for better visual integration with Leica M cameras. The barrel was later revised. The current Contax G45 conversion kit was released in June 2024, based on the 2021 concept, maintaining the original optical structure while optimizing the lens barrel's external manufacturing process, including more rational edge radii, a reworked angled chamfer on the focus ring, and a refined anodized surface finish, with no effect on optical performance or internal mechanical alignment.

Collector Notes Because this is a conversion product, the points worth checking differ from those for a factory lens. The optical core is a genuine Contax G Carl Zeiss Planar 45mm f/2, and the Funleader work is, by design, reversible. The conversion process is non-destructive, preserving the original lens components, and is designed for original Contax G45 optical assemblies with no optical modifications. Buyers should distinguish between the complete converted lens and the helicoid-only kit, which does not include the optic, and should confirm finish (silver or black) and which barrel generation they are buying, since the 2021 and 2024 versions differ externally. As with any Contax G optic, verifying the condition and coating of the original glass before conversion is sensible. No major factory military, export, or regional special variants of this Funleader conversion are widely documented.

Sources

• [1] PetaPixel (Jaron Schneider). Funleader Converts Contax 45mm f/2 G-Mount Lenses to Leica M-Mount. https://petapixel.com/2021/11/01/funleader-offers-converted-contax-45mm-f-2-lenses-to-leica-m-mount/
• [2] Funleader. Funleader Contax G45 Leica M Conversion Kit (Non-Destructive). https://myfunleader.com/products/contax-g45-f2-to-leica-m-conversion