Vintage Leica Summicron 50mm in L39 screw mount (mislabelled Zeiss), adapts to M bodies via standard ring.
This is a Leica Summicron 50mm f/2 in L39 screw mount mislabelled under Zeiss — a vintage version for Leica thread-mount rangefinders. The L39 Summicron predates the M-mount bayonet and provides Summicron quality on vintage Leica screw-mount cameras.
The L39 Summicron delivers the same quality standard as M-mount versions at the f/2 aperture class. The screw mount adapts to M bodies via standard L39-to-M adapter ring, providing cross-system compatibility between screw-mount and bayonet Leica cameras.
Build quality is vintage Leica with machined brass and chrome finish. The L39 mount uses the slower screw-thread attachment but provides identical optical quality to M-mount Summicron versions of the same era.
The L39 Summicron 50mm may offer slightly lower pricing than equivalent M-mount versions due to the less convenient screw mount. The adapter compatibility with M bodies ensures continued usefulness across the broader Leica system.